WNT3A and idiopathic interstitial pneumonia: While we observed decreased expression of Wnt3a in IPF homogenates and ATII cells (Figures 1 and 6), we proceeded with Wnt3a for the following reasons: First, Wnt3a has been repeatedly reported to potently stimulate β-catenin-dependent Wnt signaling in vitro [28], and has been recognized as the prototypic Wnt ligand for in vitro stimulations [11].