Primarily, genes related to ECM remodeling (MMP9, MMP2, HAS2, TN-C, TIMP1, FN) or general GBM markers (CHI3L1, GPNMB) seem to be mainly expressed by GBM cells as displayed by a significant downregulation of these markers in the different co-cultures. The gene discussed is MMP9; the disease is glioblastoma.