PPARG and obesity due to melanocortin 4 receptor deficiency: Indeed, most of the studies about nucleotide variations in PPARG have mainly focused on the association between a DNA variant and a specific phenotype (such as predictors of diabetes, obesity, and BMI) [57, 85–89] or related biochemical markers (plasma levels of hormones, peptides, or metabolites) demonstrated—or just supposed—to be transcriptionally regulated by PPARγ itself [78, 90–102].