CHI3L1 and central nervous system cancer: Despite the expression levels of specific genes, such as CHI3L1 and TOP2A, which have been related to necrosis in GBM14,15, and IGFBP2 and VEGFA involved in tumor progression12, mRNA-based gene expression profiling (GEP) has frequently shown discrepant results in gliomas, hampering application of GEP in clinical practice.