PECAM1 and neoplasm: Interestingly, Afonso et al. [17] compared H&E (hematoxylin-eosin) assessment with IHC (CD31, D2–40), separating single tumor cell invasion and tumor emboli, and found that tumor emboli in CD31 positive vessels remained an independent prognostic factor on multivariable analysis of overall survival (OS) in a series of 83 cases of infiltrating carcinoma.