MCL1 and dilated cardiomyopathy: Using Mcl-1 conditional knocked-out mice, Opferman’s group found that cardiac-specific ablation of Mcl-1 in cardiomyocytes resulted in a rapidly fatal dilated cardiomyopathy, which suggested that pharmacological Mcl-1 inhibition might result in an unexpected cardiotoxicity (Wang et al., 2013).