Nanotechnology, the science of developing materials containing very small fibers, is having a growing influence on daily life. Now researchers have shown for the first time in mice that long and thin nanomaterials called carbon nanotubes may have the same carcinogenic effect as asbestos: they can induce the formation of mesothelioma. The findings were observed in 10%-25% of the 32 animals included in the study, which has not yet been replicated in humans. The work appears November 6 in Current Biology.