RYR2 and catecholaminergic polymorphic ventricular tachycardia: They focused on the residue of RyR1-W4716, since mutation of this tryptophan in human RyR2 (W4645 for human, W4644 for mouse) is reported to cause CPVT (Beery et al. 2009), indicating the physiological significance of the residue.