Dr. Jie Xu is a Professor at the Institute of Biological Sciences, Fudan University. He is also an associate editor of BMC Cancer, guest associate editor of Frontiers in Pharmacology, and editorial board member of the Journal of Digestive Disease and Gastrointestinal Tumors. Dr. Xu was selected for an Excellent Young Scholar Award by the National Natural Science Foundation of China, Top-Notch Young Talents in China Award by the Chinese Government, and Tang Scholar Award by the Tang International Foundation. Also serving as a review expert for the Changjiang Scholar Program and National Natural Science Foundation of China, his research focuses on mechanisms that control the functions of cytosolic and transmembrane proteins in the contexts of tumor signaling and interactions with immune cells. Dr. Xu has published more than 50 articles in international journals, with relevant patents transferred to major pharmaceutical groups.

• Introduction.- Molecular and cellular functions of CTLA-4 pathway.- Roles of PD-1/PD-L1 pathway: signaling, cancer, and beyond.- Discovery of new immune checkpoints: family grows up.- Mechanisms of resistance to checkpoint blockade therapy.- Molecular events behind adverse effects.- Rational discovery of response biomarkers.- Spatiotemporal changes in checkpoint molecule expression.- Functions of checkpoint molecules beyond immune evasion.- Genetic alterations and checkpoint expression.- Regulations on messenger RNA: wires and nodes.- Folded or degraded in endoplasmic reticulum.- Mono- and poly-ubiquitination: tags for fates.- Lysosome as the black hole for checkpoint molecules.- Phosphorylation: a fast switch for checkpoint signalling.- Palmitoylation as a signal for delivery.- Checkpoints under traffic control: from and to organelles.- Exosome and secretion: action on?.- Macromolecules and antibody-based drugs.- Mechanisms inspired targeting peptides.- Small molecular inhibitors.- Therapeutic development of immune checkpoint blockers.- Concluding remarks