EGF and cancer: Moreover, we discuss the capabilities of 1–4 to inhibit colony formation of cancer RPMI-7951 and T-47D cells ex vivo, the suppressing influence of 1 on the epidermal growth factor (EGF)-induced colony formation of mouse epidermal JB6 Cl41 cells, and the molecular mechanism of cancer preventive effect of 1 implemented through regulation of mitogen-activated protein kinase (MAPK) signaling pathway.