In addition to PD-1, CTLA-4, and IDO, other immune checkpoints are also involved in the occurrence and development of glioma, including T cell membrane protein-3 (TIM-3; also known as HAVcr2), killer inhibitory receptors (KIR), and V-domain Ig-containing suppressor of T cell activation (VISTA). The gene discussed is IDO1; the disease is glioma.