This gene maps to a GC-rich region of the X chromosome and was identified by its proximity to a CpG island. It is thought to be a housekeeping gene. Alternative splicing results in multiple transcript variants encoding distinct isoforms.[provided by RefSeq, Dec 2008] see less This gene maps to a GC-rich region of the X chromosome and was identified by its proximity to a CpG island. It is thought to be a housekeeping gene. Alternative splicing results in multiple transcript variants encoding distinct isoforms.[provided by RefSeq, Dec 2008]