The widely studied immune checkpoints are those that target Programmed death-1/ Programmed death- ligand 1 (PD-1/PD-L1) and Cytotoxic T-cell lymphocyte associated antigen (CTLA-4) pathway.16 The cancer cells exploit these pathways to promote immune suppression and proliferate unchecked.17 Cells like B-, T- and myeloid express the immune checkpoint regulator PD-1 on their surface, whereas tumor cells produce PD-L1 along with PD-L2, which binds to the PD-1 receptor. The gene discussed is CTLA4; the disease is cancer.