Immunohistochemical section of the epithelial compartment in canines with mammary tumors shows.

*A: negative expression in the normal mammary gland ; B: low expression in benign tumor ; C: high expression in ductal carcinoma ; D: high expression in invasive Mammary carcinoma ; E: high expression in invasive papillary carcinoma ; F: high expression in intra ductal papillary carcinoma A,C,E,F: 40X, B: 4X, D: 10X.