Overexpression of EGFR in RCC with stimulation of epithelial growth factors activates tyrosine kinase in the cytoplasm, and phosphorylation of EGFR tyrosine kinase initiates a series of phosphorylation reactions that activate downstream gene expression, leading to uncontrolled cell proliferation and tumorigenesis. The gene discussed is EGFR; the disease is renal cell carcinoma.