Macrophage colony-stimulating factor （M-CSF）, also known as colony-stimulating factor 1 （CSF-1）, is a cytokine that plays a crucial role in the differentiation, proliferation, and survival of monocytes and macrophages. M-CSF is produced by various cell types, including fibroblasts, endothelial cells, and immune cells, and acts through binding to its receptor, CSF-1R, to regulate the development and function of macrophages in the immune system. In rats, M-CSF is essential for the maintenance of tissue homeostasis, immune responses, and inflammatory processes. Studies on rat M-CSF have focused on its role in regulating macrophage populations, tissue repair, and immune responses in various disease models.