Cardiac conditions that increase the late ICa,L are invariably associated with increased risk of VT/VF, including heart failure (Mewes and Ravens, 1994; Cooper et al., 2010), congenital LQT8 mutations and Timothy Syndrome (TS) (Figure 2A; Limpitikul et al., 2014; Marsman et al., 2014; Dick et al., 2016) increased pro-oxidant states, (Figure 2B; Xie et al., 2009) aging, (Zhou et al., 1998; Salameh et al., 2010), and Duchenne muscular dystrophy (Koenig et al., 2011; Viola et al., 2013) and in stem cell derived cardiomyocytes from patients with Timothy syndrome (Yazawa et al., 2011; Figure 2D). The gene discussed is CACNA1C; the disease is Timothy syndrome.