These trials included mainly ICIs, but also immunostimulatory antibodies, anti-cancer vaccines, oncolytic viruses, TLR agonists, indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors, recombinant cytokines, adoptively transferred cells, and several small molecules with immunostimulatory effects (2, 46). The gene discussed is IDO1; the disease is cancer.