ESR1 and breast cancer: Additionally, we identified the alterations of epigenetic targets, such as SWI/SNF related genes (SMARCA2, SMARCA4, SMARCA5) or histone modifiers (KMT2C or KMT2D), breast cancer-associated oncogenes (MYCN or MAPKs), or genes that are involved in drug-resistance (ESR1 and PIK3CA/B).