This gene encodes a member of the Rho GTPase activating protein family. In response to DNA damage, the encoded protein interacts with the p53 tumor suppressor protein and stimulates its tetramerization, which results in cell-cycle arrest and apoptosis. A chromosomal deletion that includes this gene is one cause of Prader-Willi syndrome, and an intronic variant of this gene may be associated with sleep duration in children. This gene is highly expressed in colon cancers and in a human basal-like breast cancer cell line. [provided by RefSeq, Sep 2016].