GPER1 and neoplasm: As a biological counterpart, the migration of CAFs promoted by both E2 and G-1 was abolished by C4PY (Fig. 5F and Fig. 6), indicating that this compound is able to interfere with relevant responses mediated by GPER also in CAFs that play a stimulatory role within the tumor microenvironment toward cancer progression (Bhowmick et al., 2004).