However, the expression levels of the TCR genes which were down-regulated in pulmonary compared to blood samples revealed fold changes showing decreased expression of CD247 (fold change −1.4, Q = 0.81) and LCK (fold change −1.5, Q = 0.77) in COPD pulmonary CD8 cells compared to S pulmonary CD8 cells, but Q values that were non-significant. Here, CD8A is linked to chronic obstructive pulmonary disease.