<p>This entry represents proteins predicted to function as serpins from various poxviruses, such as protein K3 from <taxon tax_id="10245">Vaccinia virus</taxon>. Serpins are serine protease inhibitors. Protein K3 plays an integral role in the resistance of the virus to interferon and may bind competitively to P1 kinase in order to block eIF-2-alpha phosphorylation [<cite idref="PUB00042786"/>].</p>