The stress hormone cortisol stimulates glucose production in the liver and antagonises the action of insulin in peripheral tissues—both processes have the potential to contribute to worse prognoses in people with diabetes.5, 6 Stress can also have adverse effects on cardiometabolic systems by inducing transient endothelial dysfunction, myocardial ischaemia, and cardiac arrhythmia and thus increasing the risk of fatal and non-fatal cardiac events.6 The gene discussed is INS; the disease is cardiac arrhythmia.