Shh signal originating in the basal epithelial layer of the urothelium was proposed to be received by cells in the stroma, leading to downstream expression of Gli1, Patched, and Axin2. Bladders from Gli1 mutant mice had decreased cell proliferation in the stroma after infection and this could be modulated by pharmacologic reduction or augmentation of Wnt signaling. This evidence concerns the gene GLI1 and infection.