Phospholamban-null mice in a 129 background respond to high doses of ouabain with a similar arrhythmia (9/10) and death (8/10) in the same manner as C57BL/6 WT mice (8/8, 6/8) and 129 WT mice (9/10,8/10; Figure 3C). Here, PLN is linked to Arrhythmia.