ESR1 and breast cancer: The specific role of the Androgen Receptor in breast cancer growth and progression remains uncertain, although the AR is expressed in approximately 77% of all breast cancers, even higher than Estrogen Receptors (ERs).31 A more luminal, well-differentiated, and less aggressive tumor may be indicated by high expression of Androgen Receptor in breast cancer, which could improve prognosis.32 AR inhibition tends to be well-tolerated, and patients with TNBC may benefit from it when paired with other medications, as its toxicity is much lower than that of chemotherapy.