It has been found that methylation of CpG islands in the SF-1 gene, which spans from exon II to intron III, positively regulates its expression in EnSCs in endometriosis, whereas hypomethylation of SF-1 gene CpG islands in eutopic endometrium drastically decreases SF-1 levels [238,239]. The gene discussed is SF1; the disease is endometriosis.