ESR1 and breast cancer: To determine the effect of BOLD-100 in non-stressed breast cancer cells, we treated both ER+ [MCF7, MCF7(2), MDA-MB-175] and TNBC [MDA-MB-231, MDA-MB468] breast cancer cells in regular cell culture media under basal conditions with BOLD-100 ranging from 10 to 200 μM for 72 h (Figure 1A–E).