In order to investigate the mechanism by which NNMT regulates OSCC proliferation and migration, we first excluded the non-OSCC sample in the HNSCC data (downloaded from the TCGA database), and then performed GSEA on these data to understand the molecular basis of the oncogenic property and identify the potential signaling pathways involved in NNMT expression. This evidence concerns the gene NNMT and head and neck squamous cell carcinoma.