Pro‐inflammatory cytokines IL‐1β, IL‐4, IL‐8 and IL‐17 were all significantly overexpressed in AF (p = 0.014, 0.004, 0.001 and 0.002, respectively) when compared with control tissue, while TNFα levels were no different (Figure 1). The gene discussed is IL4; the disease is atrial fibrillation.