To determine which caspase pathways are essential for induction of apoptosis by HF, ATS or HF-ATS, we performed Western blot and found that ATS increased only the level of cleaved caspase-9, but HF and HF-ATS increased the level of cleaved caspase-9 and caspase-8 (Figure 2A). This evidence concerns the gene CASP8 and hydrops fetalis.