Transcriptional repressor (PubMed:16908628). Plays a role in oligodendrocyte differentiation, together with OLIG2 (PubMed:16908628, PubMed:22355521). Mediates Notch signaling-activated formation of oligodendrocyte precursors (PubMed:16908628). Promotes differentiation of adult neural stem progenitor cells (NSPCs) into mature oligodendrocytes and contributes to remyelination following nerve injury (PubMed:22355521). Interacts with OLIG2. Detected in differentiated oligodendrocytes, from embryos at 14.5 dpc through to the postnatal stage. Up-regulated by OLIG1. Belongs to the krueppel C2H2-type zinc-finger protein family. Truncated N-terminus.