In agreement with reports showing TNFα inhibition of the expression of Smad 7 (15), a negative regulator of TGF-β–Smad2/3 signaling pathway (16, 17), HF markedly repressed (by ~5-fold) the mRNA level of Smad 7 in WT, but not L-CC1 mice (Table 4). Here, SMAD2 is linked to hydrops fetalis.