ESR1 and breast carcinoma: In particular, tamoxifen resistance is associated with enhanced glycolysis in ER-positive breast cancer cells through activation of EGFR/MAPK pathway (65, 66), a pathway also responsible for ligand-independent Erα activation (37) In the MPA-induced tumor model, the FGF-2/FGFR-2 axis drives HI growth (67).