Aligning with a previous study reporting thiram as an inhibitor blocking enzymatic activity of the TRMT6/TRMT61A complex,35 thiram treatment did not significantly affect TRMT61A protein levels (Fig. S10a), whereas the levels of m1A modification were decreased in the tumors of both 4MOSC1 and Tgfbr1/Pten 2cKO HNSCC models (Fig. S10b, c). Here, TRMT61A is linked to head and neck squamous cell carcinoma.