 Checkpoint antibody inhibitors such as Anti-PD-1-PD-L1 are a promising cancer therapeutic approach that modulate immune cell-tumor-cell interaction to suppress tumors, with four commercialized drugs targeting PD-V1, PD-L1, and CT-L84. However, the success of Anti-PD therapy is limited by insufficient and heterogeneous expression of PD-1 in the tumor microenvironment, and ongoing clinical trials are exploring combination drug therapies, safety, and future applications for multiple types of cancer. This article was authored by Hashim O'Alsab, Hashim O'Alsab, Sumrish Sao, and others.