A method of inducing dendritic cell (DC) development by administering Macrophage-Colony Stimulating Factor (M-CSF) is provided. M-CSF induces DCs to differentiate into Subtypes, for example plasmacytoid DCs and conventional DCs. Said differentiation is independent of Fms-like-Tyrosine- Kinase 3-Ligand (FL) and/or Granulocyte-Macrophage-Colony Stimulating Factor (GM-CSF). Induction with M-CSF can be achieved in vitro from hematopoietic precursors, such as bone marrow cells, or in vivo. In vitro, M-CSF-derived DCs can be used to produce cytokines and to stimulate other immune response cells. M-CSF can also be used to induce precursor cells removed from an animal to develop into DCs. In addition, these isolated DCs can be exposed to antigens to stimulate a specific immune response when reintroduced into the animal. Treatments for Cancers, such as Acute Myeloid Leukemia, and autoimmune diseases such as Systemic Lupus Erythematosus, are also provided in the invention.