Multiple signaling processes, including cell-matrix and cell-cell interactions, and growth factor/receptor binding, are crucially important for guiding blood vessel formation. Here we summarize current data, much of which has been obtained recently from gene targeting in mice, on the roles played by the growth factor ligand/ receptor tyrosine kinase systems represented by: vascular endothelial growth factor (VEGF) and its receptors; Eph/Ephrins; Tie1, Tie2 and angiopoietins; and platelet-derived growth factor (PDGF) in glomerular capillary development. A fundamental understanding of glomerular endothelial growth and differentiation during organogenesis may provide clues for stimulating glomerular repair after toxic injury or ischemia.