Among these interacting proteins, cTnI (mutant forms of which can cause hypertrophic cardiomyopathy) directly interacts with TNNI3K [19] Furthermore, homology search and phylogenetic analysis indicate that TNNI3K belongs to a tyrosine kinase-like (TLK) group within the mixed lineage kinase (MLK) kinase kinase (MAPKKKS or MAP3K) family in the human kinome tree [20,21]. Here, TNNI3K is linked to hypertrophic cardiomyopathy.