NAFLD and MAFLD include a wide spectrum of clinical features from simple steatosis, which depending on comorbidities (i.e., obesity, insulin resistance, type 2 diabetes mellitus), genetic predisposition (i.e., Pnpla3 and Tm6sf2), and diet and behavior (i.e., alcohol, cholesterol, fructose) can progress to nonalcoholic steatohepatitis (NASH). The gene discussed is TM6SF2; the disease is metabolic dysfunction-associated steatohepatitis.