CHI3L1 and astrocytoma (excluding glioblastoma): Based on previously published studies utilizing glioma patients’ urine, serum, and cerebrospinal fluid circulating marker analysis [22], we believe that combining GFAP, MMP-2, CHI3L1, OPN, and AREG expression values in patient serum will allow us to achieve this study aim: to select the most promising astrocytoma patient overall survival prediction variables from five secretory proteins—GFAP, MMP-2, CHI3L1, OPN, and AREG—and combine them with tumor markers to create a Patient Survival Score (PSS) calculation tool.