Beta-crystallin A4 (CRYBA4) is a member of the beta/gamma-crystallin family which are the dominant structural components of the vertebrate eye lens. Beta-crystallins construct aggregates of various sizes and are able to self-associate to form dimers or to form heterodimers with other beta-crystallins. The CRYBA4 gene being a beta acidic group member is part of a gene cluster with beta-B1, beta-B2, and beta-B3.