CCL2 and glioblastoma: Cx3cr1 deletion was shown to have no impact on TAM recruitment and survival of tumor-bearing mice [88], while our previous studies showed that Cx3cr1 loss, indeed, did not affect tumor-associated microglial migration in the peritumoral areas, but increased infiltration in the perivascular areas by upregulating IL-1β expression, resulting in increased CCL2 expression in a PN GBM murine model [71].