SERPINE1 and head and neck squamous cell carcinoma: We utilized the clinical data from TCGA‐HNSCC and GSE65858 (Table 1), and analysis of TCGA‐HNSCC and GSE65858 data revealed that the expression of SERPINE1 showed no significant correlation with patient gender, age, T stage, N stage, or pathological stage (Figure S1A–F).