OLIG1 is a basic helix-loop-helix transcription factor that plays critical roles in oligodendrocyte development and brain tumor biology. During normal development, OLIG1 coordinates with OLIG2 to regulate oligodendrocyte progenitor cell fate specification, directly suppressing alternative neuronal fates by binding and silencing Gsx2 enhancer elements 1. Unlike OLIG2, OLIG1 expression is specifically associated with oligodendrocyte maturation and regeneration processes, being absent in freshly isolated oligodendrocytes but expressed during process extension and membrane maintenance 2. The protein undergoes dynamic subcellular localization through acetylation-dependent nuclear export mediated by three nuclear export sequences, with acetylation at Lys150 promoting cytoplasmic retention in mature oligodendrocytes 3. In glioblastoma pathogenesis, OLIG1 functions as a master regulator of tumor cell proliferation by directly binding promoter regions of cyclins (Cdk4, Ccne2, Ccnd3, Ccnd1) and activating their transcription 4. OLIG1 and OLIG2 mutations define distinct epigenetic subgroups in pediatric glioblastoma with different anatomical distributions 5. Therapeutic targeting of OLIG1/2 can reprogram glioma stem cells toward non-proliferative fates, inhibiting tumor growth 1.