ESR1 and breast carcinoma: Recently, the mechanistic basis for pharmacological inhibition of KAT6 has been comprehensively delineated. In ER+/HER2− breast cancer cell lines that highly express KAT6A, pharmacological inhibition of KAT6A resulted in a dose‐dependent decrease in ESR1 mRNA and ERα protein expression, and weakened tumor cell proliferation and invasion.