,187 In a mouse model of HF provoked by transverse aortic constriction-induced pressure overload, gene therapy involving adeno-associated virus type 9 (AAV9)-mediated overexpression of junctophilin 2 contributed to rescuing cardiac contractility by reducing Ca2+-spark frequency, and normalizing the sarcoplasmic reticulum Ca2+-handling machinery.188. This evidence concerns the gene JPH2 and hydrops fetalis.