ASB18 (ankyrin repeat and SOCS box containing 18) is a cytosolic protein that functions as a substrate-recognition component of an E3 ubiquitin-protein ligase complex. ASB18 interacts with Cullin5 and Rbx2 through conserved BC box and Cullin5 box sequences within its SOCS box domain to form a functional E3 ubiquitin ligase complex capable of ubiquitinating target proteins for proteasomal degradation 1. The protein belongs to the 18-member ASB family of SOCS box-containing proteins, all of which display similar interactions with the Cul5-Rbx2 module 1. Clinically, ASB18 has been identified as a candidate gene harboring germline mutations potentially associated with genetic predisposition to lung adenocarcinoma in young never-smokers, with mutations detected in at least two patients in an East-Asian cohort 2. Additionally, ASB18 was identified in a genome-wide parent-of-origin effects study as a candidate locus that may increase risk for nonsyndromic cleft lip and/or cleft palate (NSCL/P) through differential parental allele contributions 3. These disease associations suggest ASB18's potential involvement in developmental and oncogenic processes, though further functional characterization is needed to establish definitive mechanistic roles in these conditions.