MMP8 and cystic fibrosis: We also showed, in an independent assay, that the enzymatic activities of another important protease, the neutrophil elastase (NE, present in primary granules), were, like those of MMP-8 and MMP-9, increased in CF PBMCs, compared to HC cells, both at homeostasis, and following PMA/iono stimulation (Figures 6G, H).