GAPDH and myocardial infarction: The westernblot result revealed that the expression level of Cx43 was decreased following MI (Protein/GAPDH, 0.16 ± 0.02 in CCR9+/+/MI group, n = 4 hearts vs. 0.74 ± 0.02 in CCR9+/+/sham group, n = 4 hearts, p < 0.01; 0.42 ± 0.04 in CCR9−/−/MI group, n = 4 hearts vs. 0.72 ± 0.03 in CCR9−/−/Sham group, n = 4 hearts, p < 0.01), while loss of CCR9 could preserve the expression of Cx43 (Protein/GAPDH, 0.42 ± 0.04 in CCR9−/−/MI group, n = 4 hearts vs. 0.16 ± 0.02 in CCR9+/+/MI group, n = 4 hearts, p < 0.01, Figures 5A,B).