CD4 and infection: We infected Gpr183Gfp/+ reporter mice (46) intranasally with 5 × 104Cn (KN99α) to induce pulmonary type 2 inflammation and found that ~60–70 % of lung-tissue resident CD4+ T cells expressed GPR183 at 10 days post-infection (dpi), with significantly higher levels than circulating CD4+ T cells (Fig. 1, A to C and fig.