The study of the cardiac gene expression by RT-PCR considering the genes: kcnd2 and kcnd3 encoding the Ito α-subunit Kv4.2 and Kv4.3, respectively (Frank-Hansen et al., 2005); kcne2 encoding to MiRP1, Ito and IKs β-subunit (Roepke et al., 2008), on tissue extracted from left ventricles of mice with STZ-induced diabetes showed significant reductions of ~80% in the expression of kcnd2 and kcne2, whereas no significant differences were shown for kcnd3 (Howarth et al., 2009). The gene discussed is KCND2; the disease is diabetes mellitus.