Although mucinous adenocarcinomas were detected in lung sections from KL mice (Figure 3D), these KRASG12C/LKB1Null tumor cells retained expression of NKX2.1 (Figure 3D, Figure 3—figure supplement 1E), and some cells also expressed the gastrointestinal transcription factor HNF4α (Figure 3—figure supplement 1E). This evidence concerns the gene NKX2-1 and colon mucinous adenocarcinoma.