Members of the Pax family of transcription factors contain a paired box DNA binding domain and may or may not contain a paired-type homeodomain and/or octapeptide region. Nine Pax genes have been identified in mammals and are divided into four subgroups based on the sequence elements present. Pax genes play a variety of roles during embryogenesis, regulating cell-lineage specification, proliferation, migration, and survival of diverse cell and tissue types. Several of the Pax genes are also expressed in cancers and serve as tumor markers.
Pax4 is known to be a key regulator for pancreatic cell differentiation and development.