GPER1 and neoplasm: The presence of GPER1 poses a clinical problem as well, as patients with GPER1 expressing tumors have a worse survival rate, compared to patients with non-GPER1 expressing tumors, when receiving tamoxifen therapy [90,91,92], mostly because tamoxifen was described to be an agonist of GPER1 [36,37,38], inducing its previously mentioned tumor-promoting capability.