Moreover, Ishibashi et al. demonstrated that CD200 expression on cancer-associated fibroblasts (CAFs) increased the efficacy of gefitinib treatment, an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) and amplified its apoptotic effects on lung adenocarcinoma cells bearing EGFR mutations. The gene discussed is EGFR; the disease is lung adenocarcinoma.