Treatment of mice harboring HSC3/EGFR-GFP tumor xenografts with gefitinib, a small-molecule EGFR tyrosine kinase inhibitor, substantially reduced tumor growth, demonstrating that HSC3/EGFR-GFP tumors require EGFR tyrosine kinase activity to sustain tumorigenesis (Figure 1F). The gene discussed is EGFR; the disease is neoplasm.