CXCL9 and neoplasm: This correlates with an increased infiltration of tumors by CD8+ T lymphocytes, which constitutes a good prognosis marker for patients with cancer.1–3 Of note, CD8+ T cell infiltration does not rely on the abundance of immunogenic peptides in the tumor, but rather on the amount of tumor-infiltrating cDC1s.43 Indeed, cDC1s express high levels of CXCL9 and CXCL10, the main factors governing the recruitment of effector CD8+ T cells into the TME.33 We find that the accumulation of CD8+ T cells indeed relies on Batf3-dependent cDC1s.