TCF7L2 and obesity due to melanocortin 4 receptor deficiency: Moreover, in some studies the associations of SNPs in PPAR-γ2 and TCF7L2 have previously been shown to be modulated by obesity status [4]. PPAR-γ2 Pro12Ala polymorphism was found more associated with T2DM susceptibility in obese populations while TCF7L2 rs7903146 T allele was shown to be more prevalent in T2DM nonobese population compared to T2DM obese individuals, suggesting a pivotal role of obesity status in genetic association with T2DM [4].