Their basic principle is based on targeting immune checkpoints that cause the tumor cell’s escape from immune surveillance, including (i) CTLA-4 inhibitors, which prevent CTLA-4 on the tumor cell from binding to B7 on the T-cell/antigen-presenting cell that causes downregulation of T-cell activity and (ii) PD-1/PD-L1 inhibitors that prevent T-cell inactivation that is a result of programmed death-1 (PD-1) (T-cell) binding with programmed death –ligand 1 (PD-L1) (on tumor cell). The gene discussed is CTLA4; the disease is neoplasm.