Immunohistochemistry is necessary and helpful for the diagnosis of EHE, can be used to confirm the origin by identifying vascular endothelial cell markers, which include CD31, CD34, VIII factor, and Friend leukemia integration 1 transcription factor.[9] In addition, several researches have shown 2 novel disease-defining gene fusions, named WWTR1(TAZ)-CAMTA1 and YAP1-TFE3, that were distinct subset of epithelioid hemangioendothelioma.[18] The differential diagnosis for EHE includes vascular malignancies such as epithelioid angiosarcoma, and other epithelioid tumors.[2]. The gene discussed is PECAM1; the disease is epithelioid hemangioendothelioma.