FOXO1 and metabolic dysfunction-associated steatohepatitis: Mechanistically, IL-15 induces FOXO1 downregulation and CXCR6 upregulation, rendering liver-resident CXCR6+ CD8+ T cells sensitive to metabolic stimuli (including acetate and extracellular ATP) and collectively triggering autoimmunity, exacerbating NASH progression (110).