Emodin increased the cytotoxicity generated by gefitinib in two non-small cell lung cancer (NSCLC) cell lines, A549 and H1650, according to Chen et al. Emodin improved a gefitinib-induced drop in phospho-ERK1/2 and Rad51 protein levels by increasing Rad51 protein instability at low dosages of 2–10 M [114]. The gene discussed is RAD51; the disease is non-small cell lung carcinoma.