The increased Src activity found in cancer cells can be caused by multiple factors, including an enhanced expression of Src activators, frequently found in cancer, such as integrins [10], EGFR [14, 42], the constitutively active mutant form EGFRvIII [43], HER2 or ErbB2 [44] or other RTKs. This evidence concerns the gene ERBB2 and cancer.