CCL2 and hydrops fetalis: The progression of HF can be measured through the heightened expression of inflammatory cytokines e.g., TNFα, IL-1, IL-6, IL-18, cardiotrophin-1, Fas ligand (FasL), monocyte chemoattractant protein 1 (MCP-1), IL-8, and macrophage inflammatory protein 1 alpha (MIP-1α) (21).