In addition to its inhibitory effect on cancer cell proliferation, ISL also induced the apoptosis of both cell lines by increasing the expression of pro-apoptotic genes C-PARP, Bax, cleaved-caspase-3 (C-caspase-3) and decreasing the expression of anti-apoptotic gene Bcl-2 as shown in Fig. 1e, f, g, h and Additional file 3: Figure S1G, H, suggesting that ISL remarkably inhibited the proliferation and induced the apoptosis of melanoma cells in vitro. The gene discussed is BCL2; the disease is melanoma.