ADRB2 and hemangioendothelioma: We then examined the steady state mRNA expression levels of ADRB1, ADRB2, and ADRB3 in a panel of malignant vascular tumor lines including 4 primary canine angiosarcoma cell lines (Emma, Frog, Jack, and SB), one mouse angiosarcoma cell line (SVR), and one mouse hemangioendothelioma cell line (EOMA), demonstrating that canine angiosarcoma lines preferentially express ADRB2 and ADRB3(Figure 1B), while malignant mouse vascular tumor lines express ADRB1 and ADRB2(Figure 1C).