SPP1 and glioblastoma: Therapeutically, inhibiting these chemokine-receptor pairs using either 4-1BB–OPN bispecific aptamers (69), the LOX inhibitor β-aminopropionitrile or neutralizing antibody (40), or the SLIT2-trapping protein Robo1Fc (70) significantly inhibits macrophage infiltration and tumor growth in GBM mouse models.