Epicardium CD31+ staining 4 days post-MI was 27.38 ± 1.99 vessels per 400x high power field in WT control (n = 4) hearts and 9.04 ± 0.73 vessels per 400× high power field in EphA2 (n = 6) control hearts after MI (p < 0.01). The gene discussed is PECAM1; the disease is myocardial infarction.