EGF and angiosarcoma: Interestingly, highly chemotherapy-resistant Emma, Frog, and SB cells derived from canine hemangiosarcoma, including CSC-enriched cultures, have demonstrated an improvement in cytotoxicity and the safety of a newly synthesized deimmunized Pseudomonas exotoxin conjugated to epidermal growth factor and urokinase (EGFuPA toxin), which are overexpressed in several tumors and particularly in sarcomas and tumor endothelial cells.