Although Zeb1-deficient cDC2 exhibited intact capability to present exogenous antigens to CD4+ T cells, they failed to fully compensate for cDC1 during CD4+ T cell priming in tumor-bearing Zeb1-dcKO mice, resulting in mild reduction of effector CD4+ T cells, probably because cDC2 did not overwhelm cDC1 at tumor sites as they did in the spleen. Here, MPPE1 is linked to neoplasm.