To examine the relationship between CTSL-based signature and immune status in TCGA patients with HNSCC, immune checkpoint expression levels were observed to be considerably higher in HNSCC patients with low-CTSL-based signature scores than in those with high-CTSL-based signature scores (Figure 8A), demonstrating that in HNSCC patients, the levels of CTSL signature scores were inversely linked with immunological state. The gene discussed is CTSL; the disease is head and neck squamous cell carcinoma.