In the context of helminth infection, Cuéllar et al. showed murine splenic CD8+ cells, which are further characterised by the expression of Foxp3, CD25 and remarkable amounts of IL-10, to be responsible for suppressive effects of the recombinant metalloproteinase Ac-TMP-2 derived from adult A. caninum15. The gene discussed is IL10; the disease is helminthiasis.