CALM2 and catecholaminergic polymorphic ventricular tachycardia: In addition to the RYR2 gene, the encoding ryanodine receptor calcium release channel and mutations in five gene-encoding proteins from the SR calcium-release complex are involved in the pathogenesis of CPVT: CASQ2 (encoding cardiac calsequestrin), TRDN (encoding triadin), CALM1, CALM2, and CALM3 (encoding identical protein calmodulin) [87].