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. Here, EGF is linked to neoplasm.