MAPK3 and malignant colon neoplasm: We previously demonstrated that, in resistant colon cancer, chronic lymphocytic leukemia, pleural malignant mesothelioma, non small cell lung cancer, and breast cancer, ERK1/2 phosphorylates and stabilizes the hypoxia-inducible factor-1α (HIF-1α), a strong inducer of Pgp [31,35,118,119,120].