FGF21 and obesity due to melanocortin 4 receptor deficiency: The network of highly upregulated pancreatic genes also included the major endocrine regulatory molecule fibroblast growth factor 21 (FGF21), increased by an average of 4.67-fold and functionally linked to IAPP; Apolipoprotein A4 (APOA4) linked to Apolipoprotein B and to Apolipoprotein A1, pro-inflammatory arachidonate 12-lipoxygenase (ALOX12: 4.10-fold) functionally linked to pancreatic Phospholipase A2 group IIA (PLA2G2A: 8.20-fold) and further linked to arginase type II (ARG2: 3.36-fold), the mitochondrial form of the enzyme which is known to be induced by obesity [41].