Unlike the severe DCM-like phenotypes in the homozygous tnnt2 mutant zebrafish, DCM caused by heterozygous (dominant) mutations in Tnnt2 is a progressive disease in human patients and usually occurs in adults (Pelliccia et al., 2017; Vischer et al., 2009). This evidence concerns the gene TNNT2 and familial dilated cardiomyopathy.