This gene contains CAG trinucleotide repeats and encodes a protein containing several stretches of polyglutamine residues. The encoded protein may be involved in the regulation of tyrosine kinase receptor signaling. This gene is located in a chromosomal region that was genetically linked to Parkinson disease type 11, and mutations in this gene were thought to be causative for this disease. However, more recent studies in different populations have been unable to replicate this association. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2013].