Interleukin (IL)-10 was cloned from the common carp (Cyprinus carpioL.) using IL-10 primers from carp head kidney following stimulation with concanavalin A and lipopolysaccharide. The cDNA consisted of a 1096 bp se-quence containing a 55 bp 5¢ untranslated region and a 498 bp 3¢ untranslated region. An open reading frame of 543 bp encoded a putative 180 amino acid protein with a putative signal peptide of 22 amino acids.