Estrogen defines the dynamics and destination of transactivated EGF receptor in breast cancer cells: Role of S1P3 receptor and Cdc42

► EGFR content is retained in endosomes by E2/S1P. ► E2/S1P-activated EGFR does not translocate to lysosomes. ► E2/S1P induce prolonged activation of Cdc42 that prevents EGFR degradation. ► S1P3 receptor mediates E2/S1P-induced activation of Cdc42.