ESR1 and breast cancer: On the basis of these data and considering that also GPER activation triggers the EGFR/ERK transduction cascade in cancer cells [45], we first assessed that the rapid EGFR and ERK activation induced by 3MC is prevented either by the AHR inhibitor CH223191 or the GPER antagonist G15 in both ERα negative and GPER positive (data not shown) SkBr3 breast cancer cells and CAFs (Fig. 2a-d).