PNPLA3 and metabolic dysfunction-associated steatotic liver disease: The PNPLA3 gene product is known to have retinyl ester hydrolase activity, and PNPLA3-I148M is associated with low serum retinol level with enhanced retinyl esters in the liver of patients with NAFLD (Kovarova et al., 2015; Mondul et al., 2015).