The sodium channel NaV1.5, which is encoded by the SCN5A gene, underlies the fast upstroke of cardiac action potential and thus plays a crucial role in cardiac electrophysiology, but the mechanism governing the regulation of NaV1.5 has not been fully elucidated. The newly developed clustered regularly interspaced short palindromic repeats (CRSPR)/Cas9 transcription factors offer a powerful and precise approach for modulating gene expression. We investigated the potential of this new tool for activating stringently silenced...