PECAM1 and ductal breast carcinoma in situ: Studies by El-Gohary and colleagues demonstrated increased mean periductal D2-40 lymphatic microvessel density and CD31 microvessel density in cases of high-grade intraductal carcinoma suspicious for invasion, concluding that that lymphatic and blood vascular densities evaluated by D2-40 and CD31, respectively, were independent prognostic indicators for patients with intraductal carcinoma of the breast [49,50].