The tumor protein D52 (TPD52) family consists of three members, TPD52, TPD52L1 (D53), and TPD52L2 (D54). These small coiled-coil motif bearing proteins interact in hetero- and homomeric fashion. The TPD52 gene maps to chromosome 8q21, and due to amplification, shows frequent overexpression in prostate and breast carcinomas. TPD52 bound to annexin VI in a Ca(2+)-dependent manner, suggesting that these molecules may act in concert to regulate secretory processes in plasma cells.