Consistent with these previous studies we found that the RyR2 is hyperphosphorylated at the CaMKII-dependent site, Ser-2814 (Fig. 6), and the expression of the catalytic and scaffolding regulatory subunits B56α and B56δ of PP2A are reduced in a canine tachypacing model of HF (Fig. 3). This evidence concerns the gene PPP2R5D and hydrops fetalis.