Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
In a roomful of stuffy diplomats, Stephen Lewis stands out for his powerful rhetoric and punchy humor. More than once, his habit for speaking uncomfortable truths has shamed governments into action.
DNA is often the most incriminating evidence in a courtroom, but sloppy analysis has sent dozens of innocent people to prison. Alisa Opar reports on the efforts to lock down error-free tests.
Thickening of the cardiac valves leads to congestive heart failure, chest pain, sudden loss of consciousness and often death. Experiments in mice now link this condition to dysregulation of an endogenous inhibitor of angiogenesis (1151–1159).
A variant gene for antigen presentation is associated with tissue damage in multiple sclerosis. The damaging effects are now shown to be dampened by an allele of a second, neighboring gene.
Presenilins are thought to contribute to Alzheimer disease through a protein cleavage reaction that produces neurotoxic amyloid-β peptides. A new function for presenilins now comes to light—controlling the leakage of calcium out of the endoplasmic reticulum. Is this a serious challenge to the 'amyloid hypothesis' of Alzheimer disease?
HIV causes a chronic infection that overwhelms the immune system and leads to T-cell exhaustion. Three groups now report that a signaling molecule that dampens immune responses may tucker out the T cells (1198–1202).
Many individuals with chronic myeloid leukemia have benefited from the drug imatinib (Gleevec)—but if they are taken off the drug, relapse occurs. Two mathematical models to explain this phenomenon, one described in this issue, have come to different conclusions (1181–1184).