APOC2 and metabolic disease: Importantly, due to the complexity of lipid metabolism and the mechanisms of gene-environment interactions in metabolic diseases, previous studies found that the genetic variants with the greatest impact on RC concentrations were found at a key point of lipoprotein metabolisms, such as apolipoprotein E (APOE), apolipoprotein C3 (APOC3), and apolipoprotein C2 (APOC2) genes encoding apolipoproteins and genes encoding enzymes involved in residue degradation, such as lipoprotein lipase (LPL) (1).