CCL2 and hydrops fetalis: Moreover, as shown in Fig. 2A, serum levels of interleukin 1β (IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), monocyte chemotactic protein 1 (MCP-1), and endotoxin (ET) were increased in the HF group compared to the NC group (P < 0.05).