TGFB1 and Obesity: Therefore, methylation levels of specific genes that are well-known players in this context were assessed in maternal saliva: Suppressor Of Cytokine Signalling-3 (SOCS3), which is upregulated in response to obesity-related stimuli [29], and Transforming Growth Factor-Beta1 (TGF-Beta1), which is a key cytokine in obesity and insulin resistance and has been reported at higher levels in women with a prior history of GDM [30].