HLA-C and diabetes mellitus: These data are consistent with previous work that found an MHC isoform switch during the onset of diabetes, i.e. decreased MHCα and increased MHCβ expression.10 MyBP-C is a thick filament-associated protein and provides an additional regulatory step to myocardial contraction.11 MyBP-C gene mutations can cause hypertrophic cardiomyopathy, 11 while its absence (cMyBP-C null mice) significantly attenuates in vivo left ventricular function.12