Probable transcription factor. In the embryo it is detected in the posterior hypotalamus and later in the head. In the adult it is detected only in testis. Expressed in a restricted region of the posterior hypothalamus from 10 dpc. Detected in the head region from 12.5 dpc to 14.5 dpc. Expression is down-regulated by 15.5 dpc. Belongs to the NK-2 homeobox family.