Ai et al. [160] reported that RyR2-S2808 phosphorylation was increased by approximately 50% in a rabbit model of HF; however, a direct test of PKA phosphorylation of RyR2 in canine and human HF yielded no difference compared with control, and a phospho-antibody against RyR2-S2808 detected equal phosphorylation levels in control and HF samples [158,161]. This evidence concerns the gene RYR2 and hydrops fetalis.