WNT1 and idiopathic interstitial pneumonia: We went on to localize cell types capable of Wnt ligand secretion, as assessed by immunohistochemistry of Wnt1 and 3a ligands, and cell types capable of Wnt signaling, as assessed by immunohistochemistry of β-catenin and Gsk-3β, in donor and IPF lung tissue (Figure 2, 3, 4, 5).