ASB-8 (ankyrin repeat and SOCS box-containing 8) is a 288 amino acid member of the ASB family that contains one SOCS box domain and four ANK repeats. Localized to the cytoplasm, ASB-8 functions as a substrate-recognition component of an E3 ubiquitin-protein ligase complex and, working in conjunction with other proteins, plays a role in the ubiquitination and subsequent proteasomal degradation of target proteins. The highest level of ASB-8 expression has been detected in skeletal muscle. ASB-8 is also expressed in heart, brain, placenta, liver, kidney and pancreas.