Otherwise, other 17β-HSDs could potentially contribute to estrogen biosynthesis with the ability to transform E1 into E2, such as 17β-HSD7 [62], 17β-HSD12 [63], 17β-HSD5 (AKR1C3) [64] and DHRS11 (dehydrogenase/reductase SDR family member 11) [65], but their contribution to the production of E2 in the different ER(+) cancer cell lines and tumors has yet to be clarified. The gene discussed is DHRS11; the disease is cancer.