STAT3 and glioblastoma: Additional presence of astrocytes in the 3D model did not affect STAT3 activation in GBM10 and GBM43, but increased STAT3 activation of the stem-like cell line GBAM1 by nearly 1.5-fold (quantified by image analysis as phosphorylated STAT3 over total STAT3, Fig 5), suggesting a greater effect of the TME on STAT3 activity of GBAM1 compared with the other GBM cell lines.