SP1 and head and neck squamous cell carcinoma: In contrast, the expression level of SP1 was significantly greater in malignant cells than in normal cells (in‐house data: p = 0.005, GSE103322: p = 0.033, GSE181919: p = 0.025) and was greater in tumor samples of advanced‐stage HNSCC (in‐house data: p = 0.005).