As is the case with other social interactions, financial transactions depend on trust. That fact is behind ingenious experiments that explore the neurobiological underpinnings of human behavior.

Developmental 'road maps' chart the steps from simple cells to mature specialized cells. A newly discovered variety of blood-cell progenitor doesn't fit into the accepted blood map, but should that map be redrawn?

DNA-cleaving enzymes trigger a repair process that can now be harnessed to correct mutations in the human genome in vitro. This represents another step towards gene-correction strategies for treating human disease.