This gene encodes a member of the paired box (PAX) family of transcription factors. Members of this gene family typically encode proteins that contain a paired box domain, an octapeptide, and a paired-type homeodomain. This nuclear protein is involved in thyroid follicular cell development and expression of thyroid-specific genes. Mutations in this gene have been associated with thyroid dysgenesis, thyroid follicular carcinomas and atypical follicular thyroid adenomas.Tissue specificity: Expressed in the excretory system, thyroid gland and Wilms tumors.ABCAM: 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.