As previously established, we observed a preserved ejection fraction and decreased infarction size in the mice presenting with reduced neutrophil infiltration (CCR1−/−) and reduced inflammatory monocyte infiltration (CCR2−/−), as well as depreciated ejection fraction and increased infarction size in mice with reduced reparatory monocyte infiltration (CX3CR1−/−) or T-regulatory cell infiltration (CCR5−/−) compared with wild-type mice undergoing a myocardial infarction procedure. The gene discussed is CCR2; the disease is myocardial infarction.