RYR2 and hydrops fetalis: S107 is another more selective rycal (Bellinger et al., 2008) with demonstrated ability to protect against ventricular arrhythmias in a mouse model with a RyR2 gain-of-function mutation (Lehnart et al., 2008) in addition to reversing the development of HF in a mouse model of constitutively phosphorylated RyR2 (Shan et al., 2010).