Although these cells are very efficient at promoting brain infection (6) and CCR2−/− mice show a decreased brain bacterial burden (9), the Lm populations in the brain and bone marrow did not converge over time during IV infection (Fig. 2C and SI Appendix, Fig. S1D), suggesting that the dominant clones in the bone marrow do not continuously and robustly invade the CNS. The gene discussed is CCR2; the disease is infection.