Targeting immune checkpoints provide novel insights into cancer therapy, and several immune checkpoint inhibitors, such as PD-1/PD-L1 and CTLA-4 inhibitors, have been used for the treatment of multiple cancers, including melanoma, kidney cancer and non-small cell lung cancer (Li B. et al., 2019; Postow et al., 2018). The gene discussed is CTLA4; the disease is melanoma.