ENTPD1 and head and neck squamous cell carcinoma: Recently published complementary data on the TME of HNSCC, NSCLC, and melanoma: i) discriminated five different implicated T-cell subtypes (e.g., naïve, activated, exhausted, effector memory, and central memory T-cells), ii) recognized that CD39+and PD-1+surface markers could accurately predict response or exhaustion, and iii) identified specific T-cell subpopulations or specific T-cell gene profiling associated with anti-PD-1 response (74).