TOP2A and central nervous system cancer: According to the significant network module from PPI network, 30 hub genes including TTK, FBXO5, KIF20A, KIF4A, LMNB1, RRM2, DTL, RAD51AP1, CDCA7, MELK, CENPK, CCNB2, KIF14, AURKA, CDK1, BUB1B, DLGAP5, CKS2, NUF2, NDC80, SMC4, NCAPG, TPX2, EZH2, HMMR, NUSAP1, TOP2A, PBK, FOXM1 and CENPF were filtered out, which were all significantly up-regulated in glioma samples by analyzing the TCGA and CGGA database.