The CYP19A1 gene encodes aromatase and is responsible for the biosynthesis of E2 via androstenedione or testosterone; this was weakly expressed in cancer tissue, with no significant differences seen between cancer and control endometrium (Pathirage et al., 2006; Smuc and Rizner, 2009; Lépine et al., 2010; Cornel et al., 2012). Here, CYP19A1 is linked to cancer.