Portrait of Jian Tang

Jian Tang

Core Academic Member
Canada CIFAR AI Chair
Associate Professor, HEC Montréal, Department of Decision Sciences
Adjunct Professor, Université de Montréal, Department of Computer Science and Operations Research
Founder, BioGeometry
Research Topics
AI for Science
Computational Biology
Generative Models
Graph Neural Networks
Large Language Models (LLM)
Molecular Modeling

Biography

Jian Tang is an Associate professor at HEC's Department of Decision Sciences. He is also an Adjunct professor at the Department of Computer Science and Operations Research at University of Montreal and a Core Academic member at Mila - Quebec AI Institute. He is a Canada CIFAR AI Chair and the Founder of BioGeometry, an AI startup that focuses on generative AI for antibody discovery. Tang’s main research interests are deep generative models and graph machine learning, and their applications to drug discovery. He is an international leader in graph machine learning, and LINE, his node representation method, has been widely recognized and cited more than five thousand times. He has also done pioneering work on AI for drug discovery, such as developing the first open-source machine learning frameworks for drug discovery, TorchDrug and TorchProtein.

Current Students

Research Intern - McGill University
PhD - Université de Montréal
Principal supervisor :
PhD - Université de Montréal
PhD - Université de Montréal
Principal supervisor :
Collaborating researcher - Wuhan University
PhD - Université de Montréal
PhD - Université de Montréal

Publications

GAUCHE: A Library for Gaussian Processes in Chemistry
Leo Klarner
Henry Moss
Aditya Ravuri
Sang Truong
Bojana Rankovic
Samuel Stanton
Yuanqi Du
Arian Jamasb
Gary Tom
Julius Schwartz
Austin Tripp
Aryan Deshwal
Gregory Kell
Anthony Bourached
Alex J. Chan
Jacob Moss
Chengzhi Guo
Simon Frieder
Alpha A. Lee … (see 8 more)
Philippe Schwaller
Johannes Durholt
Saudamini Chaurasia
Ji Won Park
Felix Strieth-Kalthoff
Bingqing Cheng
Alán Aspuru-Guzik
We introduce GAUCHE, a library for GAUssian processes in CHEmistry. Gaussian processes have long been a cornerstone of probabilistic machine… (see more) learning, affording particular advantages for uncertainty quantification and Bayesian optimisation. Extending Gaussian processes to chemical representations, however, is nontrivial, necessitating kernels defined over structured inputs such as graphs, strings and bit vectors. By defining such kernels in GAUCHE, we seek to open the door to powerful tools for uncertainty quantification and Bayesian optimisation in chemistry. Motivated by scenarios frequently encountered in experimental chemistry, we showcase applications for GAUCHE in molecular discovery and chemical reaction optimisation. The codebase is made available at https://github.com/leojklarner/gauche
Pre-Training Protein Encoder via Siamese Sequence-Structure Diffusion Trajectory Prediction
Aurelie Lozano
Vijil Chenthamarakshan
Payel Das
Self-supervised pre-training methods on proteins have recently gained attention, with most approaches focusing on either protein sequences o… (see more)r structures, neglecting the exploration of their joint distribution, which is crucial for a comprehensive understanding of protein functions by integrating co-evolutionary information and structural characteristics. In this work, inspired by the success of denoising diffusion models in generative tasks, we propose the DiffPreT approach to pre-train a protein encoder by sequence-structure joint diffusion modeling. DiffPreT guides the encoder to recover the native protein sequences and structures from the perturbed ones along the joint diffusion trajectory, which acquires the joint distribution of sequences and structures. Considering the essential protein conformational variations, we enhance DiffPreT by a method called Siamese Diffusion Trajectory Prediction (SiamDiff) to capture the correlation between different conformers of a protein. SiamDiff attains this goal by maximizing the mutual information between representations of diffusion trajectories of structurally-correlated conformers. We study the effectiveness of DiffPreT and SiamDiff on both atom- and residue-level structure-based protein understanding tasks. Experimental results show that the performance of DiffPreT is consistently competitive on all tasks, and SiamDiff achieves new state-of-the-art performance, considering the mean ranks on all tasks. Our implementation is available at https://github.com/DeepGraphLearning/SiamDiff.
Symmetry-Informed Geometric Representation for Molecules, Proteins, and Crystalline Materials
Weitao Du
Yanjing Li
Zhuoxinran Li
Zhiling Zheng
Chenru Duan
Zhiming Ma
Omar Yaghi
Anima Anandkumar
Christian Borgs
Jennifer Chayes
Hongyu Guo
Artificial intelligence for scientific discovery has recently generated significant interest within the machine learning and scientific comm… (see more)unities, particularly in the domains of chemistry, biology, and material discovery. For these scientific problems, molecules serve as the fundamental building blocks, and machine learning has emerged as a highly effective and powerful tool for modeling their geometric structures. Nevertheless, due to the rapidly evolving process of the field and the knowledge gap between science (e.g., physics, chemistry, & biology) and machine learning communities, a benchmarking study on geometrical representation for such data has not been conducted. To address such an issue, in this paper, we first provide a unified view of the current symmetry-informed geometric methods, classifying them into three main categories: invariance, equivariance with spherical frame basis, and equivariance with vector frame basis. Then we propose a platform, coined Geom3D, which enables benchmarking the effectiveness of geometric strategies. Geom3D contains 16 advanced symmetry-informed geometric representation models and 14 geometric pretraining methods over 46 diverse datasets, including small molecules, proteins, and crystalline materials. We hope that Geom3D can, on the one hand, eliminate barriers for machine learning researchers interested in exploring scientific problems; and, on the other hand, provide valuable guidance for researchers in computational chemistry, structural biology, and materials science, aiding in the informed selection of representation techniques for specific applications.
Room-temperature correlated states in twisted bilayer MoS$_2$
Fanfan Wu
Qiaoling Xu
Qinqin Wang
Yanbang Chu
Li Li
Jieying Liu
Jinpeng Tian
Yiru Ji
Le Liu
Yalong Yuan
Zhiheng Huang
Jiaojiao Zhao
Xiaozhou Zan
Kenji Watanabe
Takashi Taniguchi
Dongxia Shi
Gangxu Gu
Yang Xu
Lede Xian … (see 3 more)
Wei Yang
Luojun Du
Guangyu Zhang
PDB-Struct: A Comprehensive Benchmark for Structure-based Protein Design
Chuanrui Wang
Bozitao Zhong
Narendra Chaudhary
Sanchit Misra
Structure-based protein design has attracted increasing interest, with numerous methods being introduced in recent years. However, a univers… (see more)ally accepted method for evaluation has not been established, since the wet-lab validation can be overly time-consuming for the development of new algorithms, and the
Large Language Models can Learn Rules
Yuan Xue
Xinyun Chen
Denny Zhou
Dale Schuurmans
Hanjun Dai
An Empirical Study of Retrieval-Enhanced Graph Neural Networks
Dingmin Wang
Hanchen Wang
Bernardo Cuenca Grau
Linfeng Song
Le Song
Qi Liu
Graph Neural Networks (GNNs) are effective tools for graph representation learning. Most GNNs rely on a recursive neighborhood aggregation s… (see more)cheme, named message passing, thereby their theoretical expressive power is limited to the first-order Weisfeiler-Lehman test (1-WL). An effective approach to this challenge is to explicitly retrieve some annotated examples used to enhance GNN models. While retrieval-enhanced models have been proved to be effective in many language and vision domains, it remains an open question how effective retrieval-enhanced GNNs are when applied to graph datasets. Motivated by this, we want to explore how the retrieval idea can help augment the useful information learned in the graph neural networks, and we design a retrieval-enhanced scheme called GRAPHRETRIEVAL, which is agnostic to the choice of graph neural network models. In GRAPHRETRIEVAL, for each input graph, similar graphs together with their ground-true labels are retrieved from an existing database. Thus they can act as a potential enhancement to complete various graph property predictive tasks. We conduct comprehensive experiments over 13 datasets, and we observe that GRAPHRETRIEVAL is able to reach substantial improvements over existing GNNs. Moreover, our empirical study also illustrates that retrieval enhancement is a promising remedy for alleviating the long-tailed label distribution problem.
Evaluating Self-Supervised Learning for Molecular Graph Embeddings
Hanchen Wang
Jean Kaddour
Matt J. Kusner
Joan Lasenby
Qi Liu
Graph Self-Supervised Learning (GSSL) provides a robust pathway for acquiring embeddings without expert labelling, a capability that carries… (see more) profound implications for molecular graphs due to the staggering number of potential molecules and the high cost of obtaining labels. However, GSSL methods are designed not for optimisation within a specific domain but rather for transferability across a variety of downstream tasks. This broad applicability complicates their evaluation. Addressing this challenge, we present"Molecular Graph Representation Evaluation"(MOLGRAPHEVAL), generating detailed profiles of molecular graph embeddings with interpretable and diversified attributes. MOLGRAPHEVAL offers a suite of probing tasks grouped into three categories: (i) generic graph, (ii) molecular substructure, and (iii) embedding space properties. By leveraging MOLGRAPHEVAL to benchmark existing GSSL methods against both current downstream datasets and our suite of tasks, we uncover significant inconsistencies between inferences drawn solely from existing datasets and those derived from more nuanced probing. These findings suggest that current evaluation methodologies fail to capture the entirety of the landscape.
Towards Foundational Models for Molecular Learning on Large-Scale Multi-Task Datasets (Ultra Large Dataset)
Joao Alex Cunha
Zhiyi Li
Samuel Maddrell-Mander
Callum McLean
Luis T. Díaz Müller
Jama Hussein Mohamud
Michael Craig
Cristian Gabellini
Christopher G. Morris
Hadrien Mary
Błażej Banaszewski
Chad Martin
Dominic Masters
Scientific discovery in the age of artificial intelligence
Hanchen Wang
Tianfan Fu
Yuanqi Du
Wenhao Gao
Kexin Huang
Ziming Liu
Payal Chandak
Peter Van Katwyk
Andreea Deac
Animashree Anandkumar
K. Bergen
Carla P. Gomes
Shirley Ho
Pushmeet Kohli
Joan Lasenby
Jure Leskovec
Tie-Yan Liu
A. Manrai
Debora Susan Marks … (see 10 more)
Bharath Ramsundar
Le Song
Jimeng Sun
MAX WELLING
Linfeng Zhang
Connor Wilson. Coley
Marinka Žitnik
FusionRetro: Molecule Representation Fusion via In-Context Learning for Retrosynthetic Planning
Songtao Liu
Zhengkai Tu
Lu Lin
Rex Ying
Peilin Zhao
Dinghao Wu
Retrosynthetic planning aims to devise a complete multi-step synthetic route from starting materials to a target molecule. Current strategie… (see more)s use a decoupled approach of single-step retrosynthesis models and search algorithms, taking only the product as the input to predict the reactants for each planning step and ignoring valuable context information along the synthetic route. In this work, we propose a novel framework that utilizes context information for improved retrosynthetic planning. We view synthetic routes as reaction graphs and propose to incorporate context through three principled steps: encode molecules into embeddings, aggregate information over routes, and readout to predict reactants. Our approach is the first attempt to utilize in-context learning for retrosynthesis prediction in retrosynthetic planning. The entire framework can be efficiently optimized in an end-to-end fashion and produce more practical and accurate predictions. Comprehensive experiments demonstrate that by fusing in the context information over routes, our model significantly improves the performance of retrosynthetic planning over baselines that are not context-aware, especially for long synthetic routes. Code is available at https://github.com/SongtaoLiu0823/FusionRetro.
A Group Symmetric Stochastic Differential Equation Model for Molecule Multi-modal Pretraining
Weitao Du
Zhiming Ma
Hongyu Guo
Molecule pretraining has quickly become the go-to schema to boost the performance of AI-based drug discovery. Naturally, molecules can be re… (see more)presented as 2D topological graphs or 3D geometric point clouds. Although most existing pertaining methods focus on merely the single modality, recent research has shown that maximizing the mutual information (MI) between such two modalities enhances the molecule representation ability. Meanwhile, existing molecule multi-modal pretraining approaches approximate MI based on the representation space encoded from the topology and geometry, thus resulting in the loss of critical structural information of molecules. To address this issue, we propose MoleculeSDE. MoleculeSDE leverages group symmetric (e.g., SE(3)-equivariant and reflection-antisymmetric) stochastic differential equation models to generate the 3D geometries from 2D topologies, and vice versa, directly in the input space. It not only obtains tighter MI bound but also enables prosperous downstream tasks than the previous work. By comparing with 17 pretraining baselines, we empirically verify that MoleculeSDE can learn an expressive representation with state-of-the-art performance on 26 out of 32 downstream tasks.