SOCS (suppressors of cytokine signaling) box of ASB4 and ASB18 proteins. ASB family members have a C-terminal SOCS box and an N-terminal ankyrin-related sequence. Asb4 was identified as imprinted gene in mice. The general function of the SOCS box is the recruitment of the ubiquitin-transferase system. The SOCS box interacts with Elongins B and C, Cullin-5 or Cullin-2, Rbx-1, and E2. Therefore, SOCS-box-containing proteins probably function as E3 ubiquitin ligases and mediate the degradation of proteins associated through their N-terminal regions.