Cancer kills millions of people across the globe every year. But the development of targeted medicines, novel drug delivery technologies and clinical research data offer a glimpse towards a cancer-free future. This Outlook — a joint publication by NatureandScientific American— examines the scientific advances that are needed to propel us into a world where this ancient scourge loses its lethality.

Antibiotic-resistant infections are increasing worldwide. For instance, nearly half a million people get infected with drug-resistant tuberculosis every year, one-third of whom die. Part of the problem arises from casual overuse of life-saving medicines, rendering them worthless. As this Outlook reveals, it will take agricultural and healthcare reforms to defeat the encroaching bacterial epidemic.

Since its inception almost 15 years ago, synthetic biology has evolved into a vibrant and productive field, owing in large part to the use of model microorganisms for the design, creation and implementation of both simple and more sophisticated biological systems. This Focus issue of Nature Reviews Microbiologypresents a set of specially commissioned articles that together chart the technological and cultural developments of the field, provide a framework for the use of emerging synthetic devices for microbial engineering, discuss the use of alternative microorganisms for industrial-scale applications and describe the first successful 'real-world' application that has been achieved. The Focus issue is accompanied by a joint Web Special withNature MethodsandNature.

The ability to convert somatic cells to pluripotent cells or to a different developmental lineage holds great promise for stem cell-based therapy.

Given how common — and how dangerous — obesity is, it's amazing how little is known about the science underlying this condition. Why do some people seem predisposed to weight gain? And how does appetite actually work? Devising an effective strategy to combat the obesity epidemic will require the integration of Insights from neuroscience, genetics and the behavioural sciences.

Since its debut in 2000, synthetic biology has grown considerably and now constitutes a vibrant research discipline that promises to transform the world we live in.

About one in every one hundred people must endure the psychosis, disorientation, and social withdrawal that define schizophrenia. While there is still no effective treatment in development, scientists are learning more about the genetic and biochemical basis of this severe disorder. It is hoped that this new knowledge will one day result in new treatments that will let people living with schizophrenia lead more normal lives.

Vaccination is a triumph of preventative healthcare. But the project to erect immunological shields against deadly pathogens is far from complete — some of the most lethal diseases still lack effective vaccines. Moreover, major inequities exist in the global distribution of vaccines. Despite substantial advances in vaccine production and development, global efforts to eradicate disease through inoculation still face scientific, technological and economic hurdles.

Earth's early atmosphere is thought to have contained only small amounts of oxygen, not enough to sustain life as we know it today. The events that changed an atmosphere essentially deprived of oxygen to one that contains about 21 percent remain hotly debated. Naturepresents a Review article that discusses our latest understanding of the evolution of Earth's oxygen levels together with a selection of related content thatNaturehas published during the past ten years.

Since modern crystallography dawned with X-ray diffraction experiments on crystals by Max von Laue in 1912 and William and Lawrence Bragg (a father-and-son team) in 1913, and was recognized by Nobel prizes in physics for von Laue in 1914 and the Braggs in 1915, the discipline has informed almost every branch of the natural sciences.

In February 2004, South Korean stem-cell researcher Woo Suk Hwang rose to scientific superstardom on claims that he had created stem cells from cloned human embryos.