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). This evidence concerns the gene PNPLA3 and metabolic dysfunction-associated steatohepatitis.