SCN4B and Ventricular arrhythmia: For ventricular arrhythmia (Figure 2A), many of the significant proteins identified by the diffusion algorithm are ion channel proteins, such as those that contribute to Ca2+ (CACNA1C, CACNA1C-IT2), Na+ (SCN3A, SCN1B, SCN4B, SCN10A), or K+ (KCNQ1, KCNE3, KCNH2) transport in the heart.20