Recently, we showed that both the CPVT-causing CaM-N54I and the CPVT- and LQTS-causing CaM-N98S, as well as the LQTS-causing CaM-D96V and -D130G mutations markedly reduce inhibition of RyR2 Ca2+ release during store overload-induced Ca2+ release (SOICR) (8). This evidence concerns the gene CALM1 and familial long QT syndrome.