ESR1 and endometrial carcinoma: Since mutations and alternative splicing of ESR1 that alter the hormone-binding domain have been shown to generate hormone independence or resistance to anti-estrogen therapy in breast and endometrial cancers22, 23, 24, 25, 26, 27, 28, 29, 30, 31, related genetic alterations could play a role for therapy outcome in primary endometrial carcinoma.