SPI1 and neoplasm: Taken together, these findings highlight that in vivo cDC1 reprogramming mediated by PU.1, IRF8 and BATF3 is (i) sufficient to elicit antitumor immunity, (ii) protects from distal tumor growth and (iii) tumor growth after re-challenge, and (iv) the effects are independent of endogenous cDC1s.