Tumours were reduced when tumour-bearing mice were treated with both the CSF1R inhibitor and a C–X–C Motif Chemokine Receptor 2 (CXCR2) antagonist (to prevent PMN-MDSC migration), and tumours were completely blocked when a PD-1 antibody was added to this combination.19 This evidence concerns the gene CXCR2 and neoplasm.