TFF2 and bronchiolitis: Massive neutrophil migration into the airways is a characteristic feature in severe hRSV bronchiolitis.[6], [36] “Neurogenic inflammation” mediated by the neurokinin SP is one mechanism proposed for neutrophil recruitment and smooth muscle contraction in the airways of hRSV infected weanling rats.[8], [37] Exogenous SP has potent pro-inflammatory cytokine effects in mouse and human airway studies.[38], [39] The finding of lower concentrations of SP in the cell free airway fluid of term infants with severe disease is therefore surprising.