CHI3L1 and astrocytoma (excluding glioblastoma): The decision tree classification analysis was performed using “Classification Learner” application provided by MathWorks MatLab on TIMP-1, ANGPT-1, OPN, IP-10, TGF-β1 active, TGF-β1 latent and YKL-40 protein expression levels in astrocytoma patients and healthy control groups.