DIO1 and cardiac hypertrophy: Consistent with our previous report44, these data support the notion that attenuation of cardiac hypertrophy in PTU chow-fed mice was due, in part, to blockade of Dio2-mediated T3 biosynthesis, consistent with the role of Dio2, but not Dio1, in TH-induced NRVM growth (Fig. 2a, Supplementary Fig. 2B) and robust induction of Dio2 expression in early TAC-stressed hearts (Fig. 3c).