CXCR2 and rhabdomyosarcoma: Notably, prevention of CXCR2-mediated MDSC trafficking by anti-CXCR2 mAb therapy enhances anti-PD-1 efficacy in a mouse model of rhabdomyosarcoma, suggesting a translatable strategy to improve the efficacy of immune checkpoint blockade therapy by preventing trafficking of MDSC to the tumor site [77].