Of note, NSPs are involved in the progression of diabetic cardiomyopathy, since genetic knockout of dipeptidyl peptidase I (DPPI, also known as cathepsin C), which is an essential protease for maturation of NSPs, prevents myocyte apoptosis and fibrosis development (Kolpakov et al., 2019). This evidence concerns the gene CTSC and diabetic cardiomyopathy.