CTLA4 and non-small cell lung carcinoma: The frequency of Treg cells in PBMCs from NSCLC patients was five-fold greater than in healthy controls (10.3 vs 2.1%, P≤0.0001, Figure 3B left panel), whereas that for CD3+CTLA4+bearing lymphocytes was 10-fold greater in NSCLC patients compared to healthy controls (49.3 vs 4.8%, P≤0.0001, Figure 3B right panel) (Table 4).