CXCR4 is efficiently deleted in neutrophils from LysM^Cre/+ CXCR4^flox/− (MKO) mice. (A) Representative histograms showing cell-surface CXCR4 expression in the mature neutrophil (Gr-1^brightSSC^hi) population from bone marrow or peripheral blood or the peripheral blood B-lymphocyte (B-220⁺) population in wild-type (WT) or MKO mice. The isotype control (ISO) is shown in gray. (B) Cell-surface CXCR4 expression in the mature neutrophil population in the bone marrow or peripheral blood. Data represent the mean ± SEM. #P < .05 compared with wild-type mice; *P < .05 compared with CXCR4^+/− mice. (C) Genomic DNA was isolated from MKO or control (CXCR4^flox/− without LysM^Cre) blood neutrophils and the CXCR4 gene amplified using primers that specifically detected the deleted (CXCR4^Δ), floxed (CXCR4^flox), or null (CXCR4⁻) CXCR4 alleles.