Evaluation of STAT3 basal activity in GBAM1, GBM10 and GBM43 demonstrated that during 2D monolayer culture the cells present low to null constitutive activity (as Tyr-705 phosphorylation), but incorporation of GBM cells into the 3D Col-HA matrix induces STAT3 basal activation. This evidence concerns the gene STAT3 and glioblastoma.