METTL1 and head and neck squamous cell carcinoma: In addition, the upregulation of the METTL1/WDR4 complex and m7G levels in tRNA were also shown to promote the development and malignancy of head and neck squamous cell carcinoma (HNSCC) by regulating a subset of oncogenic transcripts, including genes related to the PI3K/AKT/mTOR signalling pathway [152].