When analyzed after 12 weeks, both c-Junfl/fl; lsl-K-RasG12D mice and lsl-K-RasG12D controls had developed multiple lung tumors that stained positive for thyroid transcription factor 1 (TTF-1), identifying them as adenocarcinomas (Figure 1D and Supplemental Figure 1A; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.124985DS1). Here, TTF1 is linked to adenocarcinoma.