The results showed that the expression level of programmed death 1 (PD-1), PD-L1, indoleamine 2,3-dioxygenase 1 (IDO), and lymphocyte-activating 3 (LAG3) in METCorC1 was higher than in METCorC2 (p < 0.05), suggesting the deep contribution of tumor immune evasion in METCorC1. The gene discussed is IDO1; the disease is neoplasm.