Empirical evidence for unifying principles in biology is often sought, but is not easily achieved. One consequence of earth's biodiversity is that exceptions to general rules are often found if one searches hard enough. For example, a popular notion in biomedicine was that parasites should inevitably evolve to become mutualistic to their hosts, because this would afford long-term survival of a parasite species that might otherwise force its host into extinction. However, theory and experiments later overturned this conventional wisdom by demonstrating that infectious parasites may evolve greater or lesser virulence ͑damage to the host͒ depending on their unique ecologies. [71] [72] [73] [74] Similarly, it should be expected that evolution of robustness and its underlying mechanism might differ substantially across the biosphere. Therefore, caution is warranted when attempting to draw widespread conclusions from the handful of valuable empirical studies on evolution of robustness. Perhaps it is possible to construct a universal theory of robustness that applies everywhere, but this is unknown. Our hope is that the exciting studies and biological examples presented here will further motivate researchers in basic science and biomedicine to consider the potential importance of genetic and environmental robustness in a great variety of biological systems. With this impetus, we may amass enough empirical data to help bridge the intellectual gap separating abundant theory on robustness evolution and application of this thinking to applied problems in biomedicine and public health. Isolation and characterization of microparticles in sputum from cystic fibrosis patients BACKGROUND: Microparticles (MPs) are membrane vesicles released during cell activation and apoptosis. MPs have different biological effects depending on the cell from they originate. Cystic fibrosis (CF) lung disease is characterized by massive neutrophil granulocyte influx in the airways, their activation and eventually apoptosis. We investigated on the presence and phenotype of MPs in the sputum, a rich non-invasive source of inflammation biomarkers, of acute and stable CF adult patients. METHODS: Spontaneous sputum, obtained from 21 CF patients (10 acute and 11 stable) and 7 patients with primary ciliary dyskinesia (PCD), was liquefied with Sputasol. MPs were counted, visualized by electron microscopy, and identified in the supernatants of treated sputum by cytofluorimetry and immunolabelling for leukocyte (CD11a), granulocyte (CD66b), and monocyte-macrophage (CD11b) antigens. RESULTS: Electron microscopy revealed that sputum MPs were in the 100-500 nm range and did not contain bacteria, confirming microbiological tests. CF sputa contained higher number of MPs in comparison with PCD sputa. Levels of CD11a(+)-and CD66b(+)-, but not CD11b(+)-MPs were significantly higher in CF than in PCD, without differences between acute and stable patients. CONCLUSIONS: In summary, MPs are detectable in sputa obtained from CF patients and are predominantly of granulocyte origin. This novel isolation method for MPs from sputum opens a new opportunity for the study of lung pathology in CF. In cystic fibrosis (CF), the lung disease is characterized by high concentrations of neutrophil chemokines, such as IL-8, and a sustained accumulation of neutrophils in the airways [1, 2] , in presence and absence of detectable infection [3] . In CF airways, neutrophils undergo conventional activation and functional reprogramming [4] [5] [6] [7] . For example, they show oxidative burst increase, enhanced production of leukotriens and elastase, increased IL-8 and decreased IL-1 receptor antagonist release (reviewed in [8, 9] ). However, the neutrophil response is not capable to clear bacteria from the CF airways ensuing in exaggerated apoptosis of neutrophils [10] [11] [12] [13] . Furthermore, neutrophils are targeted by Pseudomonas aeruginosa, the main pulmonary pathogen associated with the disease. Neutrophils killed by the bacteria release proteases that disable any neighbouring viable neutrophils [14] . Thereafter, bacterial persistence and the products of the damaged neutrophils spur further neutrophil recruitment, inducing inflammation, tissue damage and then generation of an environment that allows continued infection.