ESR1 and Uterine leiomyoma: In fact, we found that the DNA methylation status of the promoter region of ER alpha gene and GS20656 gene (differently methylated genomic loci in uterine leiomyomas) varies in even normal myometrium among individuals [11], [18], which may represent a within-physiological change in a certain cell type such as smooth muscle cells in myometrium [11], [18].