This finding implies that the unique genetic background of the GR influenced this breed’s susceptibility to the development of hemangiosarcoma, suggesting that canine tumors can be used to understand how genetic background can influence susceptibility of an individual to non-inherited cancers. Clinical trials involving tyrosine kinase inhibitor (TKI) treatment of STS found that the most effective TKIs (e.g. Sorafenib), also targeted all VEGF isoforms