Some studies based on HF gene regulatory networks have shown that the Wnt [10], TGF-β [55, 56], MAPK [57], Shh [58], BMP [59], PI3K-Akt [60, 61], Notch [62] and JAK-STAT [63] signaling pathways are widely involved in HF development, morphogenesis and circulation. The gene discussed is SHH; the disease is hydrops fetalis.