In the early stage of azoxymethane (AOM)/dextran sulfate sodium (DSS) mice model, gut dysbiosis (increased Prevotellaceae and decreased Anaeroplasmataceae) promoted tumorigenesis by stimulating CD8+ T cells activation, durable hyperstimulation of CD8+ T cells resulted in T cell exhaustion, leading to increased tumor susceptibility (66). The gene discussed is CD8A; the disease is neoplasm.