STAT3 and cardiomyopathy: Brg1 null mice embryos die when cardiomyocytes expansion and maturation begin, while in adult cardiomyocytes, Brg1 is activated by cardiac stresses and assembles a chromatin complex to activate downstream signal transduction, including HO-1 and signal transducer and activator of transcription 3 (STAT3) [10, 16–18], which are protective against ROS-induced cardiomyopathy.