An attempt based on BRG1 inhibition might be of particular importance in the treatment of double- or triple-negative breast cancer characterized by the absence of the estrogen receptor (ER), the progesterone receptor (PR) and low to normal levels of HER2, notably where therapeutic approaches targeting these proteins is impossible and patients can benefit only from less specifically targeted cytotoxic drugs. Here, ESR1 is linked to triple-negative breast carcinoma.