DLL4 and neoplasm: Here, we demonstrated using ex vivo 3D microCT images that vascular structure, density, and thickness of vasculature differ in the SS.BN3IL2Rγ- host (low-DLL4) compared with the SSIL2Rγ- host (high-DLL4), which was further supported by immunofluorescence imaging of tumor sections (Figure 1 and Figure S2).