The use of genetically engineered chimeric antigen receptor (CAR) T cells and immune checkpoint inhibitors (ICI) targeting cytotoxic T-lymphocyte associated protein 4 (CTLA4) or programmed death 1 (PD1)/programmed death-ligand 1 (PD-L1) axis has drastically improved survival in several cancer types. The gene discussed is CTLA4; the disease is cancer.