COL2A1 and glioblastoma: Thereafter, we performed intersection analysis and found that 13 genes (EHF, TRPM1, FXYD4, TP73, CDH15, LHX5, FBN3, TLX1, C1QL4, COL2A1, SEC61G, NEUROD4, and GPR139) were in the modules associated with GBM recurrence and were also differentially expressed between the recurrent and primary tissues.