In order to identify the hyper-trophic factor IL-6, signal transducer and activator of transcription STAT-3 and mitogen-activated protein kinase/ERK (MEK) signaling pathways that were associated with the cardiac hypertrophy induced by hypercholesterol diet, the protein products of IL-6, STAT3, MEK5 and p-ERK5 were measured by western blotting. Here, STAT3 is linked to cardiac hypertrophy.