CXCR4 and glioblastoma: Using synthetic protein nanoparticles (SPNPs)-mediated delivery of CXCR4 antagonist AMD3100 inhibited glioblastoma proliferation by suppressing CXCL2/CXCR4 pathway and reduced the infiltration of CXCR4+ monocytic myeloid-derived suppressor cells (M-MDSCs) [149].