PECAM1 and carcinoma: Additionally, the tumor cells in EHE exhibit strong immunostaining for the endothelial markers CD31, CD34, and ERG, retain their BAP1 expressions, and lack expressions for the cytokeratins (including CKAE1/AE3 and CK8/18), TTF-1, p40, GATA3, thus excluding carcinoma; these cells also lack expressions for the mesothelial markers calretinin, CK5/6, WT1, and D2-40, thus excluding mesothelioma (Chou et al., 2024).