Importantly, both of these cytokines have been implicated in asthma [4, 9], each defining important asthma endotypes: IL-13 is associated with the type 2 (T2)-high endotype, IL-17 with the Th17-high endotype, and IL-13+IL-17 with the mixed T2/Th17 endotype [10–12]. Here, IL17A is linked to asthma.