PDCD1 and non-small cell lung carcinoma: To clarify the characteristics of Treg cells in the TME, we compared the frequency of Treg cells and the expression of IC-molecules such as PD-1, TIM-3, TIGIT, and CTLA-4 in paired sets of tissue-derived lymphocytes, such as PBLs, pTILs, and TILs collected from 12 patients with NSCLC.