CSF1R and osteosarcoma: Pre-clinical studies of anti-TAM agents in other subtypes have shown that pexidartinib, an inhibitor of colony stimulating factor receptor-1 (CSF-1R), depletes tumour-infiltrating macrophages and suppresses tumour growth in MPNST xenografts [111], while suppressing tumour growth and increasing the infiltration of CD8+ T cells in an orthotopic osteosarcoma model [112].