IL6 and hydrops fetalis: Other types of HF, for example, hypertensive HF induced by aortic constriction, have significant increase in the infiltration of CCR2+ macrophages in myocardial tissue, as well as increased levels of local or circulating inflammatory cytokines, such as TNFα, IL-1β, IL-6 and MCP-1, suggesting that HF increases circulating monocyte-derived CCR2+ inflammatory macrophages in the heart (55, 118, 119).