Differentiation of glioma stem cells. Differentiation of glioma stem cells. Morphology of stem (COMI; DEMI; top) and nonstem (D54; U373; bottom) glioma cell lines. Cells were cultured in the presence of EGF-FGF (stem conditions) or fetal calf serum [(FCS) - differentiating conditions] for 21 days and their morphology photographed with an inverted microscope (Reprinted by permission from the American Association for Cancer Research: Mol Cancer Res 7:383–92, 2009). Guido Frosina Mol Cancer Res 2009;7:989-999 ©2009 by American Association for Cancer Research