ESR1 and metabolic syndrome: Two SNPs in ESR1, both located in the first intron, PvuII (rs2234693) and XbaI (rs9340799), are the most extensively investigated variants and reported to be associated with T2DM (Huang et al., 2006; Mohammadi et al., 2013), MetS (Zhao et al., 2018), and other diseases (Onland-Moret et al., 2005; Silva et al., 2010; Weng et al., 2015).