This gene encodes a member of the ALEX family of proteins and may play a role in tumor suppression. The encoded protein contains a potential N-terminal transmembrane domain and a single Armadillo (arm) repeat. Other proteins containing the arm repeat are involved in development, maintenance of tissue integrity, and tumorigenesis. This gene is closely localized with other family members, including ALEX1 and ALEX3, on the X chromosome. Two alternative transcripts that encode the same protein but differ in the 5' UTR have been described. Additional alternative transcripts may exist but their full length natures have not been determined. A pseudogene for this locus is located on chromosome 7. [provided by RefSeq, Jul 2008].