CSF1R and neoplasm: Importantly, blocking the CSF1/CSF1R signaling pathway using either a selective inhibitor (GW2580) or a highly potent small molecule inhibitor of CSF1R kinase (PLX3397) resulted in significant reduction in TAM infiltration and improved tumor control by RT in a mouse model (24), suggesting that the CSF1/CSFR1 axis is an important therapeutic target.