Fig. 1. Immunostaining with β-catenin monoclonal antibody showing: A, normal colonic glandular epithelium with discrete membranous staining; B, glandular epithelium of hyperplastic polyp with weak nuclear staining; C, glandular epithelium of a nonadenomatous polyp with membranous and weak cytoplasmic stain; D, glandular epithelium of Peutz-Jeghers polyp with intense nuclear staining; E, dysplastic glandular epithelium of adenoma with nuclear staining; F, moderately differentiated adenocarcinoma with prominent nuclear stain; G, weak nuclear staining in colonic mucinous adenocarcinoma; H–J, negative nuclear staining in stomach adenocarcinoma, pancreas adenocarcinoma, and ovarian mucinous cystadenocarcinoma, respectively. Magnification: A–D, ×600; E–J, ×400.