IL6 and heart failure: Previous studies have reported that the levels of inflammatory cytokines, such as tumor necrosis factor-alpha (TNFα), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) are upregulated in patients with heart failure [6, 7] and in the transverse aortic constriction- (TAC-) induced heart failure mouse model [8].