EEF2K and Parkinson disease: Using postmortem brain sections from midbrain and hippocampus of controls and PD patients (Additional file 1: Table S1), we performed immunohistochemistry (IHC) analysis of eEF2 phosphorylation on threonine residue 56 (p-eEF2, T56), which reflects eEF2K activity [42, 57].