IGFBP-rP1's expression in normal colonic epithelium and primary colon cancer. Representative images of IGFBP-rP1 detection by immunohistochemistry staining in human colonic tissue sections. Magnification: _200. A. IGFBP-rP1 expression localized to the terminally differentiated epithelium at the luminal surface of the bowel and at the tops of the colonic crypts. B. Strong expression of IGFBP-rP1 in low grade colorectal adenocarcinoma. C. Media expression of IGFBP-rP1 in medium grade colorectael adenocarcinoma. D. Weak expression of IGFBP-rP1 in high grade colorectal adenocarcionma.