<p>This domain is found in the stem cell self-renewal protein Piwi and its relatives in <taxon tax_id="7227">Drosophila melanogaster</taxon> [<cite idref="PUB00006604"/>]. It has been found in the C-terminal of a number of proteins which also contain the PAZ domain (<db_xref db="INTERPRO" dbkey="IPR003100"/>) in their central region, for example the Argonaute proteins. Several of these proteins have been implicated in the development and maintenance of stem cells through the RNA-mediated gene-quelling mechanisms associated with the protein DICER. </p>