As the late summer sun sets in the Arctic, bands of wispy, luminescent clouds shine against the deep blue of the northern sky. To the casual observer, they may simply be a curiosity, dismissed as the waning light of the midnight sun. But to scientists, these noctilucent ice clouds could be an upper-atmospheric symptom of a changing climate.

Most of us think of disease as the failure of an organ or the breach of some critical fortress in the body's defense system. But for many ailments, including cancer and diabetes, disease begins with an even more fundamental error: the failure of genes to turn on and off when they should. Hoping to understand and eventually help correct such errors scientists are developing molecules that mimic natural regulators of gene expression. New research shows that a small molecule they developed is able to turn on genes in living cells.