Vitamin D deficiency and up-regulated TNFα-related signals are reported to be involved in abnormalities including intestinal hyper-permeability, bacterial translocation, systemic/portal endotoxemia, intestinal/adipose tissue/hepatic inflammation, and hepatic steatosis in nonalcoholic steatohepatitis (NASH). The gene discussed is TNF; the disease is metabolic dysfunction-associated steatohepatitis.