EGFR is a member of the ErbB family of receptor tyrosine kinases (RTK). Activation of the receptor initiates a cascade of downstream signaling molecules, leading to cell growth and survival. This process is tightly regulated in non-transformed cells. However, constitutive activation of these pathways leads to dysregulated cell growth and proliferation, angiogenesis, and metastasis, while repressing apoptosis. Genomic damage can introduce mutations that mimic kinase activation or result in higher expression levels of EGFR.