Newly emerging concepts in blood vessel growth: recent discovery of endothelial progenitor cells and their function in tissue regeneration.

It has recently been established that bone marrow-derived endothelial progenitor cells (EPCs) are recruited to the systemic circulation and, in response to various cytokines, pharmacologic agents, and/or tissue ischemia, incorporate into sites of new blood vessel growth (neovascularization). These findings have changed our understanding of adult neovascularization by demonstrating that both preexisting endothelial cells and EPCs contribute to blood vessel formation during adult life. The following review article highlights the discovery of EPCs, their relationship to various clinical diseases, and their therapeutic potential for augmenting blood vessel formation.