GZMB and chronic obstructive pulmonary disease: In COPD, GrB–expressing monocytes and granulocytes were identified, and CD8+T infiltrating cells and apoptosis increased in airway epithelial cells, while soluble GrB levels and GrB-expressing T cells increased in BAL, suggesting that GrB upregulation in CD8+ and CD8- cells may be involved in small airway wall remodeling (27).