Abstract: This invention relates to methods of increasing the sensitivity of tumors to anti cancer therapies including antibody therapy, chemotherapy, radiotherapy, and therapies targeting cell signaling pathways such as the MAPK and PI3K pathways and receptor tyrosine kinases (e.g. EGFR). By increasing sensitivity of tumors to these agents, this invention will: (a)Prolong response in already responsive subjects; (b) Increase response rates by converting non-responsive patients into responsive patients; (c) Reverse treatment-induced resistance of tumors to anticancer therapy; and (d) Decrease treatment-associated toxicities by decreasing therapy dosages required for response. The invention also describes predictive tests, to identify patients most likely to respond to the combination treatments.