Therefore, we performed lipidomic profiling in the serum of healthy controls and patients with NAFLD in order to (1) quantify and compare different circulating phospholipid metabolites; (2) to analyze phospholipids in NAFLD-associated metabolic diseases; and finally to (3) study the association between specific circulating lipids and PNPLA3 polymorphism. This evidence concerns the gene PNPLA3 and metabolic disease.