IL1B and cystic fibrosis: Our results regarding the increase in MMP2 activity by LPS and IFN-β in CF were like those activated by IL-1β, although this cytokine induces a greater spectrum of MMPs that includes MMP-2, 3 and 9; moreover, our results are also consistent with previous reports in CF (Siwik et al., 2000; Meiners et al., 2004; Xie et al., 2004).