Cadherin 5 (CDH5), KNG1, lumican (LUM), RBP4, SERPINC1, and SERPINF1 are involved in the apoptosis of endothelial cells and related processes, and this process was predicted to be inactivated in MCO compared to that in the 1st HF (activation z-score =  − 1.985). This evidence concerns the gene KNG1 and hydrops fetalis.