Induction of SBECs in aged mice with and without oseltamivir treatment following influenza infection. A-C. The percentages of total SBEC- (A), SCGB1A1+ SBEC- (B), and SCGB1A1- SBEC-containing bronchioles (C) in the aged mice with (solid column) and without (open column) oseltamivir treatment following influenza infection. Five oseltamivir-treated and 5 untreated aged mice were used for each time-point. All error bars represent standard errors. *p < 0.05, **p < 0.01 by Student t-test. D-G. Representative immunofluorescence staining of lung sections for SCGB1A1 (green) and pro-SPC (red) at the indicated time-points following influenza infection (DAPI stain was not shown). Scale bars: 500 μm.