DPP9 enzymatic activity in hematopoietic cells is dispensable for mouse hematopoiesis

•Dipeptidyl peptidase 9 (DPP9) is a ubiquitously expressed cytosolic serine protease implicated in immunoregulation.•DPP9 knock-in enzyme inactive mice are neonatal lethal and show defects in fetal lymphopoiesis and myelopoiesis during mouse development.•The hematopoietic cells from DPP9 knock-in mice are fully functional and able to reconstitute immune system even in competitive mixed chimeras.•DPP9 enzymatic activity in hematopoietic cells is dispensable for normal mouse hematopoiesis.