Background: WDR20 (WD repeat-containing protein 20) contains five WD repeats and is a member of the WD family of proteins. The WD repeat is defined by four or more repeating units of a conserved core of approximately 40 amino acids ending with tryptophan-aspartic acid (WD). WD repeats may serve as sites of protein-protein interaction for adaptor proteins and facilitate multiprotein complex formation. WD proteins are involved in a variety of cellular processes. The function of WDR20 has not been characterized.