According to a previous study, the expression of NOX2 and NOX4 was dramatically upregulated in diabetic cardiac tissues, which promoted atrial structural remodeling through producing excessive reactive oxygen free radicals and ultimately led to AF [24], which may in turn promote the upregulation of NOX4 expression through inflammation to a larger extent, and eventually form a vicious circle between inflammation and oxidative stress [25]. The gene discussed is NOX4; the disease is atrial fibrillation.