Risako et al. treated the PC cells with the NOX4 inhibitor diphenylene iodonium and NOX4 siRNAs, the results showed downregulation of NOX4 blocked TGF-β-induced EMT phenotype including morphological changes, augmented migration, and altered expression of E-cadherin and Snail in PC cells, which showed that NOX4 transmit TGF-β-triggered EMT signals in PC [11]. This evidence concerns the gene SNAI1 and pachyonychia congenita.