ESR1 and breast cancer: Similarly to what we had seen with exogenous ERα in HEK293T cells (see Fig. 3a and Supplementary Fig. 4d), the knock-down and overexpression of Vps11/18 in MDA-MB-134 breast cancer cells increased and decreased expression of endogenous ERα target genes, respectively (Fig. 3c–e and Supplementary Fig. 4e, f).