For example, IL-17A contributes to asthma pathology by enhancing IL-13 activity25 and a dysregulated balance between IL-17A and type-2 responses exacerbates pathology during schistosomiasis and onchocerciasis.4–6,26 Understanding the relationship between IL-17A and type-2 immune responses is thus critical, and we and others have previously demonstrated that development of a full type-2 response can require IL-17A.8,12,13,27. This evidence concerns the gene IL13 and onchocerciasis.