PGP and malignant colon neoplasm: The expressions of upstream survival signals (GSK-3β, β-catenin, c-Myc and cyclin D1), downstream ABC transporters, including P-gp and MRPs, and apoptosis-related proteins, such as Bcl-2, Bax, and caspases in colon cancer cells were assessed after Epi treatment in the presence and absence of HuR knockdown or overexpression.