STAT3 and cardiac hypertrophy: The interleukin 6 (IL-6) signaling pathway is a major pathway that regulates cardiac hypertrophy, IL-6 and IL-6 receptor-activated downstream genes, such as the mitogen-activated protein kinase 5 (MEK5), extracellular signal-regulated kinase (ERKs) and calcineurin, which promotes the translocation of transcription factor-signal transducer and activator of transcription 3 (STAT3) and GATA binding protein 4 to the nucleus [16].