A key determinant of the SR calcium content is uptake into the SR via the calcium ATPase pump SERCA.25 We hypothesized that the lowered SR calcium content in BZ cardiomyocytes following MI might reflect decreased SERCA activity (KSERCA) or enhanced extrusion of calcium from the cell via the sodium-calcium exchanger. This evidence concerns the gene SLC24A3 and myocardial infarction.