This protein is a member of the paired box (PAX) family of transcription factors, typically containing a paired box domain, an octapeptide, and a paired-type homeodomain. This family plays critical roles during fetal development and cancer growth. The specific function of the PAX8 is unknown but it may involve kidney cell differentiation, thyroid development, or thyroid dysgenesis. Alternative splicing in the gene by inclusion or exclusion of exons 7 and/or 8 has produced several known products but the biological significance of the variants is unknown. Several other splice variants have been proposed but the full nature of these products has not been described. Pax8 is also a marker of otic progenitor cells.