When single tumor spheres were dissociated to single cells and subsequently cultured in adherent differentiating condition, these single cells differentiated into NeuN, OLIG2, or GFAP expressing neurons, oligodendrocytes, or astrocytes, respectively (Fig. 4b), thus indicating that U251 TS are capable of multi-lineage differentiation. The gene discussed is GFAP; the disease is neoplasm.