ESR1 and endometrium neoplasm: Estrogen receptor 1 (ESR1) is a ligand-induced steroid hormone receptor that mediates estrogen signaling and regulates transcriptionally driving growth, proliferation, and differentiation including cellular processes, in many breast and uterine It functions as an oncogene in endometrial tumors (Blanchard et al. 2019; Shanle and Xu 2010).