CXCL12 and ischemia: The three distinct rRIPoC methods induced a sustained rise of SDF‐1α mRNA expression in the myocardium, of 32.0% increase for every half day, 31.4% for every 1 day and 16.9% for every 2 days compared with that in IR group at 3 days after ischemia (P < 0.01); 85.8%, 82.5%, 69.3% at 7 days after ischemia (P < 0.01); 81.7%, 78.4%, 63.8% at 14 days after ischemia, respectively (P < 0.01).