ESR1 and breast carcinoma: The pegylated form of this antagonist, PEG-LPrA2, attenuated the expression of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor type 2 (VEGFR2) in MCF-7 (ER + human breast cancer cells) and MDA-MB-231 (ER-human breast cancer cells) breast cancer in mice [114].