The results demonstrated classification tree composed of three proteins—active TGF-β1, TIMP-1, YKL-40, and correctly classified 78.0% (103/132) of the whole sample, 71.7% (43/60) of healthy control sample and 83.3% (60/72) of astrocytoma sample (Fig. 3). Here, CHI3L1 is linked to astrocytoma (excluding glioblastoma).