Preclinical studies showed that PPARγ2 is needed to promote healthy AT expansion, promoting redistribution of fat mass towards the scWAT, in mice but is also required for the β-cell expansion adaptive response to IR (Medina-Gomez et al. 2007) In line with the critical role of PPARγ in preventing metabolic disorders, epidemiological studies showed that specific polymorphism of the PPARγ gene affect metabolic traits and susceptibility to diabetes (Heikkinen et al. 2007). This evidence concerns the gene PPARG and diabetes mellitus.