Histological examination results. Anti-Shh treatment effects. Hematoxylin and eosin and immunohistochemistry Ki-67 staining (all images in original magnification ×100). Compared with controls, xenografts treated with 5E1, cyclopamine, or forskolin show a reduction of viable glands and proliferative cells. Treatment of xenograft mice with 5E1 and forskolin significantly reduces tumor growth (P = 0.007 and P = 0.049, respectively), proliferation (Ki-67–positive cells), and viable gland density compared with controls (P < 0.001).