SMARCA1 and angiosarcoma: An alternative interpretation is that, regardless of the ontogeny of the tumor-initiating cell, the transformation events responsible for hemangiosarcoma involve pathways that render VEGF signals mostly inconsequential and other pathways controlled at the level of transcriptional regulation (e.g., by SMARCA1) and/or survival (e.g., acid ceramidase) are important determinants of the breed-dependent phenotype.