TNF and hydrops fetalis: Several key pathways involved in cashmere goat HF development and cycling include tumor necrosis factor (TNF), MAPK signaling pathway, WNT pathway, fibroblast growth factor (FGF) family, bone morphogenetic protein (BMP) family, transforming growth factor (TGF) family, Sonic hedgehog (SHH) conduction pathway and NOTCH signal transduction pathway [3, 15–18].