alpha-ERKO ERalpha- Esr1<tm1Unc> Null/knockout ERalphaKO http://identifiers.org/mgd/MGI:2150897 AERKO Esr1tm1Ksk MGI:2150897 ERalpha-KO targeted mutation 1, Kenneth S Korach ERa-Neo ER-alpha<-> alphaERKO ERalphaKOCH ER1KO ERKO Esr1<tm1Ksk>