Csf1, also known as macrophage colony-stimulating factor, is the primary growth factor essential for the control of monocyte and macrophage differentiation, survival, proliferation and renewal [2]. It is widely expressed, mainly by cells of mesenchymal lineages, and is involved in the CSF1/CSF1R signaling pathway, which is crucial in macrophage recruitment and functional regulation [3].

In a Csf1 CKO mouse model where Csf1 was depleted in marrow adipogenic lineage precursors using AdipoqCre, there was increased femoral trabecular bone mass, diminished osteoclasts in the femoral secondary spongiosa region, and reduced bone marrow cellularity, hematopoietic progenitors, and macrophages, demonstrating that Csf1 from these precursors is required for osteoclast formation and hematopoiesis in bone [1].

In conclusion, Csf1 is vital for the development, homeostasis, and tissue repair related to monocytes and macrophages. Gene-knockout mouse models, such as the Csf1 CKOAdipoq mice, have revealed its role in bone remodeling and hematopoiesis, highlighting its significance in understanding these biological processes and potentially related disease conditions.