PNPLA3 and fatty liver disease: In preclinical studies, knock-in mouse models with the previously mentioned human PNPLA3 i148M gene variant resulted in decreased liver steatosis (p = 0.038) in the liver inflammation score (p = 0.018) and fibrosis stages (p = 0.031) in homozygous PNPLA3 i148M/M knock-in mice.