In this context, G9a promotes the EMT and invasive CSC properties via diverse mechanisms, including epigenetic silencing of epithelial markers (Dong et al., 2012), hypoxia response (Casciello et al., 2020), metabolic reprogramming (Dong et al., 2013), and obesity-mediated BC progression (Figure 5A; Chang et al., 2015; Si et al., 2015; Siouda et al., 2020). This evidence concerns the gene EHMT2 and breast cancer.