Preclinical studies have suggested that upregulation of ER stress (ERS)-related proteins, including binding immunoglobulin protein (BIP), Bcl-2 associated X protein (Bax), Bcl-2 homologous antagonist/killer (Bak), and C/EBP homologous protein (CHOP), occurs in animal models of HF [6, 7]. This evidence concerns the gene BAK1 and hydrops fetalis.