BATF3 and neoplasm: To test whether the loss of IRF8 had a functional consequence on tumor outgrowth by acting through the loss of cDC1s rather than the expansion of granulocytes, we measured the growth of PyMT-mCh-OVA tumors in IRF8−/− mice, which lack cDC1s and have expanded granulocytes, and Batf3−/− mice, which only lack functional cDC1 (Supplementary Fig. 7c)18,41.