Transcription factor that binds preferentially to a variant of the octamer motif (5'-ATGATAAT-3'). Isoform C1 and isoform C2 are found in the brain, while isoform C7 is found in the testis. Expressed in the embryo throughout post-implantation stages with the most prominent expression in the developing CNS. In the adult, it is highly expressed in brain whereas weaker expression can be detected in other organs. Belongs to the POU transcription factor family. Class-6 subfamily.