NFKB1 and hydrops fetalis: The increased level of TNF-α in the brain in HF leads to the activation of multiple signaling pathways, particularly to the activation of NF-κB and mitogen-activated protein kinase (MAPK) pathways that are important to TNF-α-induced inflammatory cascades and sympathetic activation (Wei et al., 2008; Diaz et al., 2020; Wei et al., 2021).