Tumor trafficking of myeloid-derived suppressor cells is inhibited by CXCR2 deficiency in a mouse model of rhabdomyosarcoma [35] and data from a mouse model of colitis-associated cancer suggests that CXCR2 is required for recruitment of myeloid-derived suppressor cells [24], [36]. Here, CXCR2 is linked to rhabdomyosarcoma.