NPPB and hydrops fetalis: Based on the above observations, we formulated following working model(Fig 8):pressure overload by TAC activate MAPK1/2 and AKT, leading to HF; SalB could inhibit the phosphorylation of ERK1/2,but not PI3K/AKT pathway, decreasing the expression of transcription factor GATA4 and BNP protein translation, so as to inhibit HF.