Innate lymphoid cells (ILCs) are a diverse group of immune cells that lack expression of lymphocyte and myeloid cell surface markers and regulate immune responses through cytokine production. Monticelli et al. identified ILCs in the lungs of healthy mice and humans. These cells were CD90+, expressed interleukin-5 (IL-5) and IL-13 in response to IL-33, and were dependent on the transcription factor ID2 for their development. Lung ILC populations were found to expand following infection of mice with influenza virus, and depletion of these cells with a CD90-specific antibody, or the blockade of IL-33 signalling, compromised lung function and airway remodelling. In accordance with this, lung ILCs were found to express several genes implicated in wound repair, including that encoding amphiregulin. Interestingly, administration of amphiregulin to ILC-depleted mice following influenza virus infection ameliorated lung pathology.