C11orf9 (chromosome 11 open reading frame 9), also known as MRF (myelin gene regulatory factor), Ndt80, KIAA0954 or MGC10781, is a 1,151 amino acid single-pass membrane protein that localizes to nucleus. A member of the MRF family, C11orf9 is expressed in the ARPE-19 cell line, brainstem, uterus and, to a lesser extent, in basal ganglion and liver. C11orf9 is weakly expressed in cerebellum and retina. C11orf9 contains one NDT80 DNA-binding domain and acts as a transcription factor that is required for expression of central nervous system (CNS) myelin genes such as MBP and MOG, thereby playing a central role in oligodendrocyte maturation and CNS myelination. C11orf9 exists as two alternatively spliced isoforms and is encoded by a gene located on human chromosome 11, which consists of approximately 135 million base pairs and 1,400 genes. Chromosome 11 makes up around 4% of human genomic DNA and is considered a gene and disease association dense chromosome.