The many facets of SDF-1alpha, CXCR4 agonists and antagonists on hematopoietic progenitor cells. - Faber A; Roderburg C; Wein F; Saffrich R; Seckinger A; Horsch K; Diehlmann A; Wong D; Bridger G; Eckstein V; Ho AD; Wagner W (Journal of Biomedicine & Biotechnology, 2007)