Notably, we found that the relative abundance of CXCR6high effector memory in CD4 T cells positively correlated with lung function in the E-COPD group (Fig. 7h), mirroring the overall effector memory CD4 correlation (Supplementary Fig. 8a) and no significant correlations were observed between CXCR6Low CD4 effector memory and lung function (Supplementary Fig. 8b). This evidence concerns the gene CD4 and chronic obstructive pulmonary disease.