Purity >95% by SDS-PAGE, MW: 15.2 kDa. Interleukin 3 (IL-3) is a cytokine that is produced by activated T cells and mast cells. IL-3 induces the differentiation of hematopoietic stem cells into myeloid precursor cells, such as erythrocyte, megakaryocyte, granulocyte, monocyte, and dendritic cells. IL-3 also functions in the nervous system and is important during the B-1 cell regulation of chronic inflammatory diseases.