Mesenchymal glioblastoma, a phenotype associated with poor clinical outcomes, is characterized by the expression of CD44 and chitinase 3-like protein 1 (CHI3L1) in mesenchymal glioma stem cells (GSCs). CHI3L1 has been implicated in several oncogenic pathways driving mesenchymal differentiation. However, the role of CHI3L1 as a paracrine modulator of GSC states, as well as the transcriptional regulatory network induced by CHI3L1 in GSCs, remains unknown.