PTPRZ1 and glioblastoma: In contrast, non-MES cells treated with selumetinib were associated with induction of glial differentiation genes, such as Olig1, Olig2, Sox10, Ptprz1, and Pdgfra (Figure 3F and Supplemental Figure 12F), though it is possible this difference could be explained by selection of a clonal subpopulation rather than activation of a differentiation program in non-MES glioblastoma cells.