Thus, the main aim of this study was to globally quantify m6A modification by the mass spectrometry approach and determine the mRNA expression level of selected m6A RNA methyltransferase (METTL3), demethylase (FTO), and m6A readers (YTHDF2, YTHDC2) in 45 HNSCC patients and 4 cell lines (FaDu, Detroit 562, A-253 and SCC-15) using qPCR. Here, METTL3 is linked to head and neck squamous cell carcinoma.