Expression of ELF-1 during vascular development and tumor angiogenesis. (A) Immunofluorescence staining in the developing dorsal aorta and B16 melanoma tumors for Tie2 (green) and ELF-1 (red), and colocalization (yellow) with DAPI staining (blue) for detection of cell nuclei. (B) Immunostaining for ELF-1 within endothelial cells of a Matrigel plug, supplemented with bFGF (80 ng/mL), injected subcutaneously into C57BL/6 nu/nu mice with an isotype-matched control.