STAT3 and infection: In line with these observations, Stat3-deficient multifocal hyperplasia at 6 and 13 weeks as well as in situ ACs at 6 weeks post AdCre infection displayed significantly enhanced cell proliferation compared with tumours from Stat3-proficient control littermates (Supplementary Fig. 1f), whereas the low amount of apoptosis observed in the KrasG12D-driven lung tumours was not altered upon genetic ablation of STAT3 (refs 21, 22; Supplementary Fig. 1f).