Therefore, we investigated the roles of T and B lymphocytes and group 2 innate lymphoid cells (ILC2s) in airway inflammation and remodelling, and lung function in an experimental model of COPD using mice that specifically lack these cells (Rag1−/− and Rorafl/flIl7rCre [ILC2‐deficient] mice). The gene discussed is RAG1; the disease is chronic obstructive pulmonary disease.