CSF1 and head and neck squamous cell carcinoma: Furthermore, Shin et al. reported that CD200 blockade using sCD200R1-Ig-expressing adenovirus (the Fc domain of an antibody fused with the CD200R extracellular domain) not only diminished the activity of the β-catenin/S100a4-RAGE/NF-κB/M-CSF signaling pathway and inhibited growth of CD200-expressing HNSCC tumors, but also reversed the polarization of M2 macrophages back to an M1 phenotype.