Medullary thyroid cancer (MTC) accounts for less than 5% of all thyroid cancers, and it is a rare neuroendocrine tumor which derives from calcitonin-secreting thyroid C cells.Given the underlying mechanism involved in MTC remain unclear, the development and the specific pathways of MTC require further investigation.here we employed the application of TMT6plex-based LC-MS/MS to identify and analyze the novel differentially-expressed proteins(DEPs) from MTC patients, To our best knowledge, it is the first study to comprehensively investigate the molecular mechanisms of MTC by proteomics technology from Chinese MTC patients’ tissues, and these DEPs identified in our study will provide a better understanding of the underlying pathophysiology of MTC, as well as may provide potential therapeutic targets for patients with MTC.