PECAM1 and Wilms tumor: Immunohistochemical staining is positive for vimentin, calretinin, cytokeratin 5/6 (CK 5/6) and Wilm’s tumour-1 (WT-1), suggesting mesothelial origin, and is typically negative for thyroid transcription factor 1 (TTF 1), BErEP4 antibody, endothelial markers like CD31 and CD34, factor VIII and vascular endothelial growth factor receptor 3 [13].