In humans, several variants in the TNNI3K gene have been associated with altered kinase activity and various cardiac phenotypes, including conduction disease (CCD), dilated cardiomyopathy (DCM), supraventricular arrhythmia, and SCD (Figure 1B) [30,31,32,33,34]. Here, TNNI3K is linked to familial dilated cardiomyopathy.