Genotypic differences, such as single nucleotide polymorphisms, may contribute to the development of heart failure by the MYH7 Q315R variant, as similar genetic mutations can cause different phenotypes in various mouse strains.6 For this reason, we crossed the MYH7 Q315R variant mice with the C57BL/6NJcl sub-strain. Here, MYH7 is linked to heart failure.