Cancer cells display a broad spectrum of alterations that include gene rearrangements, point mutations and gene amplifications, leading to disturbances in molecular pathways regulating cell growth, survival and metastasis. When such changes manifest in majority of patients with a specific type of tumor, these can be used as biomarkers for detection and developing targeted therapies, besides predicting responses to various treatments (Hanahan and Weinberg, 2000; Ludwig and John, 2005).