CCR2KO BMT reduces leukocyte infiltration into the heart following MI. (A) Representative CD68, tryptase, and MPO staining for the border zone of hearts from WT C57BL/6 mice receiving WT, β2ARKO, or CCR2KO BMT that underwent MI surgery. Arrowheads indicate positive staining. Insets show higher magnification at 250×. (B–D) Quantification of CD68 (B), tryptase (C), and MPO (D) staining for the border zone of 4-d post-MI hearts from WT, β2ARKO, and CCR2KO BMT mice. n = 4–8; one-way ANOVA, †P < 0.01 vs. WT BMT, ‡P < 0.001 vs. WT BMT; ns, not significant. Data are expressed as mean ± SEM.