IL6 and atrial fibrillation: Because of its secretion by adipose tissue, it has been termed an adipokine20 but like other cytokines, IL-6 is secreted by many other different cells, including endothelial cells, fibroblasts, myocytes, macrophages, and T cells.13 IL-6 is involved in structural and electrical remodelling associated with AF21,22 (Figure 4) and it has been suggested to be an independent predictive factor for early AF recurrence after direct current cardioversion.23