TWIST1 and angiosarcoma: This is further strengthened by our findings that also vascular tumors such as hemangioblastomas and angiosarcomas display SLUG and TWIST expression in similar cellular association as seen in gliomas, while in hemangiopericytoma – a tumor considered to be of pericytic origin – the majority of tumor cells were moderately to strongly SLUG- and TWIST-positive (Supplementary Figure 2).