RFXAP, RFX5, RFXANK and CIITA are all associated with MHC II expression, and mutations in any of them lead to MHC II deficiency, which may result in immune evasion in CRC (Michel et al., 2010; Axelrod et al., 2019). The gene discussed is RFX5; the disease is hyperinsulinemic hypoglycemia, familial, 4.