Exosomal-TIM-3/gal-9, and CD73/CD39 are also being investigated as immunotherapy biomarkers, respectively, in NSCLC or HNSCC patients, and were found to be associated with many indicators of tumor progression, i.e., an aggressive phenotype, higher tumor burden, advanced stages of cancer, and more frequent distant metastasis [59,72]. Here, ENTPD1 is linked to head and neck squamous cell carcinoma.