These data are supported by previous studies that demonstrate that the BZ region has reduced SERCA expression, calcium transient amplitude, and contraction at 3–7 days following MI.13,33 In contrast, the amplitude of calcium release, SR calcium content, and SERCA activity was not significantly different between the BZ and RZ region in Runx1-deficient mice post-MI demonstrating homogeneous calcium handling across regions that is likely to contribute to the improved LV contractile function observed in Runx1-deficient mice at 1-day following MI. The gene discussed is RUNX1; the disease is myocardial infarction.