Ankyrin repeat and SOCS box protein 13(ASB13) is a member of the ankyrin repeat and SOCS box-containing (ASB) family. ASB13 contain six ankyrin repeats sequence and a SOCS box domain. The SOCS box serves to couple suppressor of cytokine signalling (SOCS) proteins and their binding partners with the elongin B and C complex, possibly targeting them for degradation. ASB13 may be a substrate-recognition component of a SCF-like ECS (Elongin-Cullin-SOCS-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins.