Although the exact mechanism by which GL derivatives enhance the anticancer effect of CDDP is unclear, it has been known that activation of EGFR contributes to enhance anti-apoptotic effect by chemotherapeutic agents [57,58,59], therefore, the suppression of EGF signaling by GL derivatives mediated by PGRMC1 might enhance the anti-cancer effect of CDDP. Here, EGFR is linked to cancer.