STAT3 is the most important effector of the JAK2 in the initiation and development of cardiac hypertrophy.9 After phosphorylation, STAT3 translocates from the cytoplasm to the nucleus and promotes the transcription of multiple hypertrophic factors including ANP and BNP.23Therefore, it is worthy to examine whether the expressions/activities of STAT3 are interfered by HSF1 in hearts upon acute ischemia. Here, JAK2 is linked to cardiac hypertrophy.