A) Baseline lung function parameters [whole lung resistance (R), Newtonian resistance (Rn), tissue resistance (G), compliance (C), elastance (E), tissue elastance (H)] were examined on flexiVent in WT and Htr4−/−-naive animals. Age-adjusted least-squares means and sems are plotted. B) Total cells were counted from BALF of untreated mice (n ≥ 20 mice/genotype). Mean values per group with sem are plotted. *P < 0.05 vs. WT.