ERBB3 and cancer: It has emerged as a promising therapeutic target in cancer by using monoclonal antibodies.46 Vorinostat was reported to revert the mesenchymal phenotype and enhance the antitumor effect of gefitinib by inducing both E-cadherin and ErbB3 expressions.47 In our hands, the class I HDACi shows even lower EpIC-50 in inducing the ERBB3 promoter activities than that in CDH1. This suggests that restoring ErbB3 expressions might be easier to achieve to overcome the epigenetic barriers.