In line with these and the present findings, erlotinib, an orally administered inhibitor of the EGFR, prevented development of pulmonary metastases in a spontaneous pulmonary metastasis breast cancer mouse model, where expression of EGF and EGFR turned out to be strong in pulmonary metastatic nodules compared with primary breast cancer [29]. The gene discussed is EGFR; the disease is metastasis.