cDC1 are instrumental in spontaneous rejection of breast cancer NOP23, especially during the phase of T‐cell priming. (a) Tumor growth (mean ± SEM) in control (n = 5), in constitutively cDC1‐depleted (Xcr1‐DTA, n = 6) or conditionally cDC1‐depleted (Karma‐tmt‐DTR + DT) female mice. Karma‐tmt‐DTR mice were injected 4 times with DT every 60 h, starting 1 day before engraftment (n = 5, representative of 3 independent datasets), at d + 4 post‐engraftment (n = 5, representative of 2 independent datasets) or at d + 8 post‐engraftment (n = 5, representative of 2 independent datasets). (b) Tumor volumes as measured in a at days 10, 18 and 26. Data are shown as mean ± SEM, with values for individual mice shown as white circles. ns, not significant (P > 0.05); *, P < 0.05; **, P < 0.01; and ***, P < 0.001; non‐parametric Mann–Whitney U‐test. (c) Analysis of CD40 and CD86 expression by flow cytometry on TdLN Mig‐cDC1 and Res‐cDC1. The data shown are from one experiment representative of two independent ones.