 The peptidase CD26 DPPIVdipeptidyl peptidase IV removes dipeptides from the amino terminus of proteins and thereby inactivates these cleaved proteins. It was shown, that CD26 cleaves SDF-1 into a non-mitogenic molecule. Inhibition or deletion of CD26 leads to an increased homing of hematopoietic progenitor cells to the bone marrow after transplantation by increasing the invasion capacity of these cells Campbell et al. 2008; Christopherson et al. 2004. 