In hematology, myelopoiesis in the broadest sense of the term is the production of bone marrow and of all cells that arise from it, namely, all blood cells. But in a narrower sense that is also commonly used, myelopoiesis is the regulated formation specifically of myeloid leukocytes (myelocytes), including eosinophilic granulocytes, basophilic granulocytes, neutrophilic granulocytes, and monocytes.