Macrophage colony-stimulating factor 1 (CSF1) (CSF1)

Macrophage colony-stimulating factor 1 (CSF1), also known as M-CSF, is a cytokine and growth factor that plays a critical role in the regulation of the mononuclear phagocyte system. It acts by binding to its cognate receptor, CSF1R (CD115), to stimulate the survival, proliferation, and differentiation of monocytes, macrophages, and bone-resorbing osteoclasts. In the context of oncology, CSF1 is often overexpressed by tumor cells, leading to the recruitment and polarization of tumor-associated macrophages (TAMs) that create an immunosuppressive microenvironment and promote tumor progression, angiogenesis, and metastasis. Beyond cancer, the CSF1/CSF1R axis is involved in inflammatory diseases, bone disorders, and neurodegenerative conditions where microglial activity is central. Therapeutic strategies targeting this pathway include monoclonal antibodies that neutralize the CSF1 ligand or block the CSF1R receptor, as well as small-molecule tyrosine kinase inhibitors that prevent downstream signaling. Clinical applications have shown significant efficacy in tenosynovial giant cell tumors (TGCT), and ongoing research explores its potential in combination with immune checkpoint inhibitors to overcome resistance in various solid tumors.

Other names

M-CSFCSF-1LCSFMCSFMacrophage colony-stimulating factor

Neutralization of the CSF1 ligand by monoclonal antibodies or inhibition of the CSF1R receptor by antibodies and small-molecule tyrosine kinase inhibitors to prevent downstream signaling and deplete tumor-associated macrophages.