Finally, when inoculated on Basic Leucine Zipper ATF‐Like Transcription Factor 3 (Batf3)−/− mice lacking cDC1 cells, the tumor growth disadvantage of Smad4KO PDAC and KPC‐1199 tumors was nearly completely reversed (Figure 3F; Figure S3G, Supporting Information). This evidence concerns the gene MPPE1 and neoplasm.