Although intriguing possibilities are that inhalation of a nebulized mist containing DPPIV and/or PAR2 agonists might be useful as therapeutics for ARDS, and localized delivery of these neutrophil chemorepellents might be useful in other neutrophil-driven diseases, caution will be needed to limit dosing to prevent systemic toxicity. This evidence concerns the gene DPP4 and acute respiratory distress syndrome.