RYR1 and catecholaminergic polymorphic ventricular tachycardia: Iyer et al. solved the cryo-EM structures of two gain-of-function RyR mutations, RyR1 R164C and RyR2 R176Q, both located in an equivalent position of NTD-A, that are associated with MH and CPVT, respectively (Iyer et al., 2020).