CXCR2 and neoplasm: There was a strong increase in CD11b+ CD11c− Ly6Ghi Ly6Clo cells in in the spleen of PyMT−Cxcr2−/− animals compared to PyMT animals (Figure S6A), which was similar to Cxcr2−/− animals suggesting that this increase was related to Cxcr2 inactivation and not to the presence of a tumor.