MAPK3 and malignant colon neoplasm: We show here that RS5517 synergized with β-catenin inhibitors FH535 and pyrvinium pamoate in triggering massive apoptosis of Ls174T and DLD1 colon cancer cells (Fig. 9a, b), thereby preventing persistent ERK1/2 phospho-activation mediated by single-β-catenin targeting (Fig. 9c).