Mice were instilled with vehicle (A, C, E) or ATP (B, D, F) followed by vehicle (A, B) FGF receptor inhibitor PD173074 (PD; C, D), TGFα receptor inhibitor AG1478 (AG; E, F) or both (G). Representative images of a single confocal plane depicting BrdU-IR from ectoturbinate 2 are shown. Dotted lines demark the OE. Arrowheads indicate the basal cell layer. Scale bar = 50μm. (G) Quantification of BrdU+ cells in endoturbinate II and ectoturbinate 2. * p<0.001 v. vehicle. #, p<0.001 v. ATP.