CCR2 and influenza: During this influenza infection, the majority of immigrating inflammatory cells are from CCR2+ monocytic parents [3]; mice lacking CCR2 not only have decreased accumulation of monocytes after influenza infection but also decreased mortality and lung damage [3, 16, 17], with CCR2−/− mice exhibiting decreased lactate dehydrogenase (LDH, a measure of damaged and therefore leaky epithelium) in the BAL fluid.