KCNN4 and cardiac arrhythmia: Probably, thanks to the multiplicity and intrinsic redundancy of ion channels in the cardiac pacemaker, our work showed that inhibition of SK4 K+ channels rescues in vitro the cardiac arrhythmias exhibited by hiPSC‐CMs derived from CPVT2 patients carrying the CASQ2 D307H mutation and by SAN cells isolated from CASQ2‐D307H KI mice.