In rodent models of diet-induced nonalcoholic hepatitis (NASH), FGF-21 deficiency exacerbates hepatic steatosis, inflammation, and fibrosis, while FGF-21 supplementation attenuates these pathological changes and reduces NASH markers level (Fisher et al., 2014; Tanaka et al., 2015). The gene discussed is FGF21; the disease is metabolic dysfunction-associated steatohepatitis.