CTLA4 and non-small cell lung carcinoma: In NSCLC, higher peripheral CD8+CD28− T cells, CD4+CD25+FOXP3+ regulatory T cells, CTLA-4+ cells (in both CD4+and CD8+T cells), proliferating CD8(+) T cells, and lower CD4+T cells and CD4/CD8 ratios have been observed when compared with healthy controls [26, 28–30].