PECAM1 and neoplasm: Immunohistochemical examination indicates that the tumor cells were diffusely positive for Factor VIII, Fli-1, CDK4, INI-1, MDM2, vimentin, focally positive for AE1/AE3, CD31 and negative for actin-sm, CD34, desmin, myoD1 and S-100 (Fig. 3).