MELK and astrocytoma (excluding glioblastoma): We considered MELK and STMN1 gene expression status according to the median relative expression values of GBM (scores ≥ median values were defined as increased expression and scores < median values as decreased expression for both genes MELK and STMN1.The definition of MELK and STMN1 mRNA expression status was scored according to the median expression values (2−∆Ct) of each grade of astrocytoma.