POSTN and glioblastoma: In turn, the most relevant genes to explain the GBM cluster were the CHI3L1, ANXA1, IGFBP3, COL1A2, COL1A1, NNMT, COL3A1, PDPN, POSTN, VEGFA, PTX3, TOP2A, HS3ST3B1, IGF2BP3, LOX, SHOX2, XIST and IBSP genes.