By day 11 of infection, a timepoint that approaches peak ILC2 activation in the lung of WT mice,26 infected ΔILC2 mice had increased lung eosinophils, increased ILC2 numbers, and increased IL-5 and IL-13 expression by lung ILC2s as compared to WT mice, consistent with a role for CISH in restraining ILC2 activity in response to tissue perturbation (Fig. 2g–j). This evidence concerns the gene CISH and infection.