This gene encodes a protein containing a potential N-terminal transmembrane domain and multiple armadillo (arm) repeats. Proteins containing arm repeats are involved in development, maintenance of tissue integrity, and tumorigenesis. This gene is located in a cluster of related genes on chromosome X. There is a pseudogene for this gene on chromosome 7. Alternative splicing in the 5' UTR results in multiple transcript variants encoding the same protein. [provided by RefSeq, Aug 2013].