IL5 and helminthiasis: Our finding that ILC2 are the major source of the type 2 cytokine IL-5 (as well as IL-13, data not shown) and that ILC2 produce extremely high levels of this cytokine on a per cell basis, are in keeping with recent findings on type 2 cytokine production by ILC2 in a model of experimental helminth infection [10], [12].