Disclosed are adenovirus vectors comprising a ROBO4 enhancer/promoter operatively linked to a transgene. Also disclosed are adenovirus vectors comprising a chimeric AD5-T4 phage fibritin shaft, a trimerization domain displaying a myeloid cell-binding peptide (MBP), and a ROBO4 enhancer promoter operatively linked to a transgene. Also disclosed are methods of expressing a transgene in an endothelial cell in vivo, comprising administering to a mammal an adenovirus comprising a ROBO4 enhancer/promoter operatively linked to a transgene. Also disclosed are uses of the adenoviral vectors, including mobilization of granulocytes, monocytes and lymphocytes from bone marrow, mobilization of cancer cells in vivo, selective targeting of endothelial cells, and cancer treatment methods.
