IL-1α fragments, similar to those produced by GrB, were found in BAL in human airway inflammatory diseases, as COPD, cystic fibrosis and bronchiectasis (8), while GrB activity on IL-1α was demonstrated in vivo in GrB knockout mice (29), strongly suggesting that this activity also exists in vivo. Here, GZMB is linked to chronic obstructive pulmonary disease.