ARF1 and neoplasm: The tumor numbers in the Lgr5/Arf1/Apc/IFNγ-KO and Lgr5/Arf1/Apc/Rag1-KO also significantly increased in comparison with those in the Lgr5/Arf1/Apc mice (Lgr5/Apc: 99.6 ± 8.9; Lgr5/Arf1/Apc: 41.0 ± 5.6; Lgr5/Arf1/Apc/Rag1-KO: 90.4 ± 11.0; Lgr5/Arf1/Apc/IFNγ-KO: 73.0 ± 9.5) (Fig. 4g–i).