Aside from the novel insights into the effects of CaM-F142L on RyR2 regulation, our single RyR2 channel experiments support our previous finding that both CPVT- and LQTS-causing CaM mutations (N98S, D96V, and D130G) result in aberrant RyR2 regulation (8). Here, RYR2 is linked to familial long QT syndrome.