Recent findings indicate that classical Wnt/β-catenin signaling is a key contributor to renal fibrosis.[15, 16] Additionally, macrophages are a major source of functionally active Wnt ligands.[13] For this reason, the role of the Wnt/β-catenin pathway in HO-1- mediated effects needs to be clarified. Here, HMOX1 is linked to renal fibrosis.