NOX4 and silicosis: In order to understand the potential roles of Wnt/beta-catenin signaling and NOX4 in the development and progression of a silicotic lung, the expression of several key components of Wnt/β-catenin signaling cascade and NOX4 protein and the fibrotic and fibrogenic factors in the lungs of SiO2-induced silicosis mice were ascertained by immunoblotting (IB) and immunofluorescent staining (IF) assays.