NOX4 and neoplasm: TGFβ ligands are potent inducers of Nox4 expression, fibroblast activation in vitro and in vivo and are abundantly expressed by epithelial cells in premalignant prostatic intraepithelial neoplasia (PIN) lesions and tumor cells in PCa.8 We therefore performed dual Nox4 ISH and IHC for TGFβ1/2/3 ligands on the same PCa tissue section to determine their spatial expression in PCa.