YY1 and cardiomyopathy: Although the role of YY1 in cardiomyocyte differentiation, cardiac development, and cardiomyopathy has been previously explored (Sucharov et al., 2003; Morikawa et al., 2013; Beketaev et al., 2015), studies of the involvement of YY2 in cardiovascular development and diseases have been limited, albeit that YY2 expression was detected in mouse hearts during both embryogenesis and postnatal stages (Drews et al., 2009).