In contrast, some other cross-sectional and nested case–control studies (including 57–374 cases) reported that elevated IGF-1 levels were associated with lower prevalence or incidence of coronary artery disease [3, 4, 11], heart failure [6], atrial fibrillation [13] and ischaemic stroke [7, 14]. The gene discussed is IGF1; the disease is atrial fibrillation.