The number of lineage-labeled (GFP+) AT2 cells re-entering the cell cycle was significantly increased in SftpcCreERT2; Rosa26miR-302; Rosa26mTmG lungs, as compared with SftpcCreERT2; Rosa26mTmG control lungs both before (0 days after infection [dpi]) and 7 dpi infection with Streptococcus pneumoniae strain T4 (SpT4; Figure 1, A–C). The gene discussed is SUPT4H1; the disease is infection.