Interestingly, in the detection of clinical samples (Figure 2A) and in the analysis of scRNA-seq sample clusters (Figure 4C), DUSP9 showed relatively different expression levels in different patients, which suggests that DUSP9 is a highly plastic gene in HNSCC tumors and may be used for molecular classification of HNSCC tumors 24, 30. This evidence concerns the gene DUSP9 and head and neck squamous cell carcinoma.