Members of this family are found in class II invariant chain-associated peptide (CLIP), and are required for association with class II major histocompatibility complex (MHC) in the MHC class II processing pathway [1].

1: Crystal structure of MHC class II I-Ab in complex with a human CLIP peptide: prediction of an I-Ab peptide-binding motif. Zhu Y, Rudensky AY, Corper AL, Teyton L, Wilson IA; J Mol Biol. 2003;326:1157-1174. PMID:12589760