In mouse lines meant to mimic hypothyroidism (TRα and TRβ KO), TRβ KO mice demonstrated no alterations in HCN expression level or HR, whereas the TRα KO had decreased HR and a reduction in both HCN2 and HCN4 expression levels, implying that the effects of T3 on HCN channel expression occur through activation of TRα (Gloss et al., 2001). This evidence concerns the gene MALAT1 and hypothyroidism.