CD200R1 and non-small cell lung carcinoma: Although an increased number of the transcription factor FoxP3+ Tregs and programmed cell death protein (PD-1)+ cells were observed in CD200R-expressing stromal cells, the expression of CD200 in NSCLC increased the levels of cytotoxic T lymphocytes (CTL), natural killer (NK) cells, and T helper (Th)1 cytokine, IL-2 and interferon-gamma (IFNγ)[115-117].