MPPE1 and cancer: Type 1 conventional dendritic cells (cDC1) perform non-redundant functions in anticancer immunity.1 2 Mice deficient in cDC1s (eg, Batf3–/–) display lower spontaneous rejection of immunogenic tumors and decreased responses to T cell based immunotherapies.1 In humans, a cDC1 gene signature positively correlates with improved overall survival (OS) in patients with cancer and with responses to checkpoint blockade immunotherapy.1 2 A key role of cDC1 is to prime tumor antigen-specific CD8+ T cells.