The present invention relates to mutations in Epidermal Growth Factor Receptor (EGFR) and KRAS and methods of detecting such mutations as well as prognostic methods for identifying tumors that are susceptible to anticancer therapy such as chemotherapy and/or kinase inhibitor treatment. The methods involve determining the presence of a mutated EGFR gene or mutated EGFR protein and/or a mutated KRAS gene or mutated KRAS protein in a tumor sample.
