In mouse asthma models that use ovalbumin (Kim et al., 2012), house dust mite (HDM) (Wilhelm et al., 2011; Halim et al., 2012a; Klein Wolterink et al., 2012), papain (Halim et al., 2012a), and fungal allergens, ILC2s uniformly increase in number and are the major source of IL-5 or/and IL-13, especially in the early phases of the disease. Here, IL5 is linked to asthma.