When used in combination with radiation therapy, epicatechin was also shown to increase the sensitivity of Panc-1, U87, and MIA PaCa-2 cancer cells to radiation, enhancing the activation of certain cellular signaling pathways involved in cell cycle regulation, including Chk2 phosphorylation and p21 induction, albeit only in cancer cells, and not in normal cells [17]. This evidence concerns the gene CHEK2 and cancer.