TTN and aortic stenosis: In alignment with this observation, the PKG-dependent phosphorylation status of Ser4099 within the elastic N2-Bus sequence of titin was also reduced in diabetic AS patients relative to non-diabetic AS patients (Fig. 5G; AS−DM: mean ± SEM: 13.71 ± 0.7539 a.u.; AS+DM: 11.42 ± 0.5985 a.u.).