ERBB4 and heart failure: Abundant evidence has shown that the activation of ErbB2 (also named HER2/neu) or ErbB4 prevents cardiomyopathy [132,133], the while inhibition of ErbB2 or ErbB4 causes heart failure [134,135,136,137], possibly through the modulation of Akt, eNOS, and myosin light chain kinase, an enzyme critical for cardiac muscle contraction [138] (Figure 2).