TTR and thyroiditis: For this purpose, we applied a combination of immunoprecipitation and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) to analyse the PTM pattern of TTR in serum of patients with thyroid disease that reveal a dysregulation of thyroid hormone metabolism 16,17, and compared these results with the patterns obtained from serum of healthy controls.