CD28 and lung cancer: To investigate and compare the significant CD8+ T cell markers between healthy volunteers and patients with lung cancer, a flow cytometer was used for further detection of CD16, CD25 (IL2Rα), CD28, CD122 (IL2Rβ), CD178 (FasL), CD183 (CXCR3), and CD279 (PD-1) (Table S1).