RYR2 and hydrops fetalis: The ICa, Ito, IKs, SERCA2a and RyR2 protein expressions, total Csqn and Kup were decreased in HF simulations, producing a prolonged APD (S1A Fig) and an increased Ca2+ transient amplitude (S1B Fig) and SR Ca2+ content (S1D Fig), which are in agreement with experimental results [18].