All four foetal gene expression levels were significantly elevated after ORAB surgery as compared to sham, but the data also substantiate the evidence for the step-like difference in HF development previously described, as mRNA levels of NPPA and MYH7 were significantly higher in ORAB 0.55 compared to ORAB 0.66 (Fig 6, panel A and C). The gene discussed is MYH7; the disease is hydrops fetalis.