TTN and heart failure: Reduced all-titin phosphorylation contribute to the development of heart failure, against the reduced phosphorylation, increased phosphorylation has been demonstrated in heart failure, the PKCα-dependent phosphosite at S11878 within the PEVK-titin segment was hyperphosphorylated in HFpEF animal models (Hamdani et al., 2013a, 2014; Linke and Hamdani, 2014; Franssen et al., 2016).