PNPLA3 and metabolic dysfunction-associated steatotic liver disease: Interestingly, interactive exploration of the metabolic network around tributyrin using the HumanCyc—an encyclopedic reference on human metabolic pathways—showed that some key NAFLD-related enzymes, including PNPLA2, PNPLA3, and PNPLA4 participate in the conversion pathway of tributyrin (BioCyc Id CPD-13014) to butanoate (Supplemental Fig. 1).