RYR2 and catecholaminergic polymorphic ventricular tachycardia: Murayama et al. also found that two CPVT-associated mutations (RyR2(human)-C4193W and RyR2(human)-A4607P) near the caffeine-binding sites greatly increase Ca2+ sensitivity by altering the hydrophobic interaction (Murayama et al. 2018b).