PLAU and glioblastoma: Although our results are not uniformly showing an increase of each of the invasive markers tested in all of the cell lines tested, the increase in uPA and/or gelatinase seen in some of the GBM cells exposed to osmotic or hydrostatic pressure is in agreement with previous results showing that GBM cells placed in agarose hydrogels and exposed to 50% compressive strain showed increased mRNA expression of both uPA and uPA receptor by a factor 2–3, as well as cathepsin B and PAI235.