HF inhibited proliferation and induced apoptosis in the absence of exogenous TGFβ, but addition of the latter potentiated the effects of HF and resulted in a reduction of the ED50 concentration by 45% and further up-regulated the expression of TGFβRI, SMAD3 and p21. Of note, as shown in figure 6, the addition of TGFβ alone to NB4 cells was able to up-regulate its target genes. Here, TGFB1 is linked to hydrops fetalis.