Holmgaard et al. used PLX647 to inhibit the CSF-1R in B16 murine melanoma cell lines transfected with indoleamine 2,3-dioxygenase (IDO), a dioxygenase which contributes to a worse prognosis by inducing the recruitment of MDSCs to the tumor site [111], and detected a reduction in CD11b+ Gr1int MDSCs with a subsequent repolarization towards anti-tumoral behavior and an increase in cytotoxic lymphocyte tumor infiltration and activity [92]. This evidence concerns the gene CSF1R and melanoma.