HSPA5 and hydrops fetalis: The overloading of Ca2+ stimulated the binding with CaMKII to enhance the phosphorylation of CaMKII and CREB (Figure 3(b)), meanwhile, the levels of GRP78 and Caspase-12, ERS related proteins, were upregulated in HF mice (Figure 3(c)), suggesting that ERS can cause the degradation of SERCA2a, resulting in decreased cardiac diastolic function.