KIT and gastrointestinal stromal tumor: Examples of the later, where predictive molecular biomarkers are also critical nodal targets of a tumor maintenance pathway are c-KIT mutations in gastrointestinal stromal tumors (GIST) [44, 45] and Epidermal Growth Factor Receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) [46-49] that predict response to and are both targets of tyrosine kinase inhibitors (TKIs).