GPER1 and cancer: In normal breast tissues, GPER is moderately expressed (Uhlén et al., 2015) and has been detected in diverse cancer cell lines and malignant tumors, such as endometrial carcinoma (He et al., 2009), ovarian cancer (Albanito et al., 2007), melanoma (Fábián et al., 2017), prostate cancer (Chan et al., 2010), thyroid cancer (Vivacqua et al., 2006), and testicular germ cell tumors (Franco et al., 2011).