OLIG2 and glioblastoma: Recent miRNA surveillance of GBM tumors also revealed that oligodendrocyte lineage cells (Olig2+, NG2+, O4+) and macrophages (Iba1+, CD163+) were increased at the border of these tumors, with three of the top miRNAs (miR-219-5p, miR-219-2-3p, and miR-338-3p) in this region relating to oligodendrocyte differentiation (33).