Figure 2. Cyclopamine completely inhibits corneal epithelial proliferation in vivo. A: Immunostaining of corneal epithelium 2 h after injection with BrdU in control mouse injected with vehicle only. Five BrdU-postive nuclei are labeled. B: Immunostaining of corneal epithelium 2 h after injection with BrdU in mouse injected with 32 mg/kg cyclopamine. No BrdU-positive nuclei are detectable, and no positive nuclei were detected in any section of the corneas of 3 cyclopamine-treated mice.