CD44 and glioblastoma: To further study the possible mechanism by which CDCP1 promotes the transformation of PN-GBM to MES-GBM, we identified 10 key genes through the above strategies, among which some genes (CD44 [49], STAT3 [50], IL6 [51], and TLR2 [52]) have been reported to be related to the migration and invasion of GBM cells; therefore, CDCP1 is indeed related to the migration and invasion of GBM.