RYR2 and hydrops fetalis: One study has demonstrated that transgenic mice with an absent PKA phosphorylation site on RyR2 are protected against MI-induced HF (Wehrens et al., 2006); however, others have shown that CaMKII-mediated RyR2 phosphorylation leads to altered Ca2+ sparks as opposed to PKA-mediated phosphorylation (Li et al., 2002; Guo et al., 2006).