There was a significant decrease in the percentage of CD28null/CD8- and CD28nullCD8+ T cells and NKT-like cells expressing GCR in both COPD groups and controls compared with their CD28+ T and NKT-like cells (Data for T cell and NKT-like cell subsets from COPD group shown in Figure 2a and b respectively) (data for controls not shown). Here, CD28 is linked to chronic obstructive pulmonary disease.