Despite of some discrepancies, the main observations are that the peak INa, Scn5a mRNA, and Nav1.5 protein are reduced during heart failure in both human patients and animal models (Baba et al., 2005; Valdivia et al., 2005; Xi et al., 2009; Dybkova et al., 2018). The gene discussed is SCN5A; the disease is heart failure.