ESR1 and neoplasm: Estrogen receptor α (ERα) mediates as nuclear receptor (NR) the hormonal breast cancer (BC) development [1,2,3], being stimulated by 17β-estradiol (E2); the initialization of tumor progression is regulated by either genomic direct or indirect pathway [4,5,6,7,8,9,10,11], as well as by the recruitment of transcriptional basal machinery (TBM) complex (see Supplementary Material: Introduction for further information and references).