This SR Ca2+ leak has been associated with an increase in PLN/SERCA ratio responsible for a delayed [Ca2+]i transient decay and diastolic dysfunction, also seen in HFpEF with chronic kidney disease (Primessnig et al., 2016) and in human HF with EF > 45% (Hohendanner et al., 2013; Ljubojevic et al., 2014). The gene discussed is PLN; the disease is hydrops fetalis.