Fig 1C, Table 2 and Table 3 contain representative ECG and M-mode echo data from 10-week-old STIM1+/–and WT mice anesthetized with isoflurane (1%). The ECG demonstrated no arrhythmias and no differences in ECG parameters between STIM1+/–and WT mice. The LV ejection fraction (EF), LV wall thickness, end diastolic volume, and LV mass determined by echo were unaffected, suggesting normal heart development and preserved cardiac contractile function in STIM1+/–mice at 10 weeks of age. This evidence concerns the gene STIM1 and Arrhythmia.