To further confirm the importance of Mcl-1 in SNS-032-induced apoptosis in ESCC cells, KYSE30 cells transfected with a plasmid encoding human Mcl-1 were incubated with SNS-032 for 48 h, and the influence of ectopic expression of Mcl-1 on SNS-032-mediated apoptosis was examined by western blotting and trypan blue exclusion assay. The gene discussed is MCL1; the disease is esophageal squamous cell carcinoma.