GPER1 and breast cancer: In addition to controlling cancer cell growth, GPR30 activation by antiestrogen tamoxifen upregulated expression of Connective Tissue Growth Factor (CTGF) via transactivation of its promoter by AP-1 to promote cell migration in SKBR3 breast cancer cells [234], shedding light onto the GPR30-mediated stimulatory effects on breast cancer cell metastatic potentials.