YKL-40 is a mesenchymal marker which is named as ‘human cartilage glycoprotein-39 or chitinase-like protein-1’ and probably has an important role in migration and motility of glioma stem cells (GSCs) and their differentiation into endothelial cells, that is why it has a role in angiogenesis [61]. The gene discussed is CHI3L1; the disease is glioma.