Likewise, in atrial cardiomyocytes from patients with long-standing persistent atrial fibrillation (AF), some studies reported RyR2 dysfunction and increased SCaE incidence [9,10,11,12,13], while others showed reduced SCaE incidence and calcium-signaling silencing (Figure 2) [14,15,16,17]. The gene discussed is RYR2; the disease is spinocerebellar ataxia with epilepsy.