GPER1 and breast neoplasm: Additionally, GPER participates in the paracrine secretion of chemotactic, growth, and ECM-related factors by CAF, thereby triggering invasive behavior in breast tumor cells (Pupo et al., 2012), including F-actin reorganization, epithelial-mesenchymal transition (EMT), cancer cell migration, and angiogenesis (De Francesco et al., 2014).