The function of cysteine-rich hydrophobic domain-containing protein 1/2 (CHIC1/2) is not clear. CHIC1, also known as brain X-linked gene (BRX), is preferentially expressed in the brain and is a potential candidate for one of the X-linked mental retardation syndromes mapped within the pericentromeric region of the human X chromosome []. A chromosomal aberration involving CHIC2 is found in a form of acute myeloid leukemia; the mutation prevents palmitoylation and the protein does not associate with the membrane [].