In the present study, we show that in SkBr3 breast cancer and HepG2 hepatocarcinoma cells E2 and G-1 induce the expression of miR144 and down-regulate the levels of Runx1 through GPER and the involvement of the PI3K/ERK1/2/Elk1 transduction pathway. This evidence concerns the gene GPER1 and breast carcinoma.