BAG3 and diabetes mellitus: BAG3 levels can be altered by various mutations in the BAG3 gene, but even in the absence of a mutation, elevated BAG3 levels have been found to be secreted by cardiomyocytes in response to stress, and also in the serum of patients with heart failure, hypertension, and hypertension with type 2 diabetes mellitus (T2DM) [19].