A recombinant therapeutic agent which is chemically identical to or similar to the endogenous protein cytokine macrophage colony-stimulating factor (M-CSF). Synthesized endogenously by mesenchymal cells, M-CSF stimulates the survival, proliferation, and differentiation of hematopoietic cells of the monocyte-macrophage series and can reverse treatment-related neutropenias. Recombinant M-CSF may also enhance antigen presentation and activate antitumoral cytotoxic T-cells.