SPAG1 and central nervous system cancer: Major discriminator between high-grade and low-grade tumors included CRYAB, IPYR, TPIS, PEA15, PSD13, GFAP, IDH3A, 6PGL, PHP14, KCRB as overexpressed in low-grade gliomas; HCD2, HBA, HBD as overexpressed in high-grade GBM.