CCL2 and central nervous system cancer: The stark increase in CCL2 peaked our interest, as it is essential for regulating the regulatory T cell response and stimulating immunosuppression in GB (Chang et al., 2016), and can promote tumor invasiveness (Zhang et al., 2012), while inhibition of its main receptor CCR2 reduces myeloid infiltration and improves the effect of checkpoint inhibition in glioma (Flores-Toro et al., 2020).