Homeobox Protein B8 (HOXB8)

HOXB8 is a member of the Antp homeobox family and encodes a nuclear protein with a homeobox DNA-binding domain. The encoded protein functions as a sequence-specific transcription factor that is involved in development. Increased expression of this gene is associated with colorectal cancer. Mice that have had the murine ortholog of this gene knocked out exhibit an excessive pathologic grooming behavior. This behavior is similar to the behavior of humans suffering from the obsessive-compulsive spectrum disorder trichotillomania.RNA fragments diagnostic of miR196-directed cleavage of HOXB8 were detected in mouse embryos. Cell culture experiments demonstrated downregulation of HOXB8, HOXC8, HOXD8, and HOXA7 and supported the cleavage mechanism for miR196-directed repression of HOXB8.