In recent years, monoclonal antibodies targeting immune checkpoints have been approved by the FDA for the treatment of various cancers including colorectal, gastric, and various haematological malignancies.402 These antibodies promote T cell activation by interfering with inhibitory signalling caused by receptor-ligand interactions between effector T cells and tumour cells, such as PD1-PDL1, CD80-CTLA4 and CD86-CTLA4. The gene discussed is CTLA4; the disease is cancer.