Co-localization of Shh and Perlecan, and correlation with Ki-67 staining. Immunohistochemistry for Sonic Hedgehog (A), demonstrating both weak cytoplasmic staining in prostate cancer epithelial cells and stronger intraluminal staining of secreted SHH. Co-localization of Perlecan (B) and Sonic Hedgehog (C) in consecutive sections of prostate carcinoma. Examples of co-localization of the secreted proteins in gland lumens are highlighted (red asterisks). All histologic images originally photographed at 400 × magnification. Significant co-localization of Perlecan and SHH staining was associated with higher cellular proliferation rates as indicated by Ki-67 nuclear staining by immunohistochemistry (D).