Wnt3a promotes the formation of a myofibroblast-like phenotype in cultured fibroblasts, in part, by upregulating TGF-β signaling, whereas studies in mice show that stromal Wnt3a activates canonical Wnt signaling in the epithelium, facilitating progression of PIN lesions to adenocarcinoma [98,99]. This evidence concerns the gene WNT3A and prostate intraepithelial neoplasia.