Checkpoint proteins were extensively studied concerning diseases like AIDS, Cancer, TB, etc. Significant checkpoint inhibition MAbs primarily target the proteins like Cytotoxic T-lymphocyte-associated protein 4 (CTLA4), mucin domain-containing protein 3 (TIM3), Programmed cell death 1 ligand 1 (PD-L1), etc. and hence enhance the activation of effector T-cell by eliminating T-cell inhibition. The gene discussed is CTLA4; the disease is cancer.