Immune checkpoint inhibitors (ICIs)—namely, cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed death 1/programmed death ligand 1 (PD-1/PD-L1) inhibitors—have revolutionized the treatment of advanced cancers by improving patient survival across a wide range of tumors [13]. The gene discussed is CD274; the disease is cancer.