Although we previously reported that arecoline could induce oxidative-stress responsive proteins in oral squamous cell carcinomas, such as haem oxygenase-1 18 and metallothionein-1 19 and it could be inhibited by NAC treatment, but here we found that arecoline-induced ZEB1 expression in BMFs was independent of ROS induction (Fig. 6A). The gene discussed is ZEB1; the disease is oral cavity squamous cell carcinoma.