Analysis by Singh et al. [142] of DNA methylation data in glial and glioneuronal tumors revealed a positive correlation between monocyte proportion and expression of PD-L1 and PD-L2 in glioma/glioneuronal cells, suggesting monocyte-mediated immunogenicity in glioma/glioneuronal cells which may be an area of interest for developing future immunotherapies. This evidence concerns the gene PDCD1LG2 and central nervous system cancer.