By putting the pieces of a chemical puzzle into the right order, a thorny problem in catalysis has been solved. This opens the door to syntheses of molecules that contain the useful trifluoromethyl group.

The organization of behaviour as sequences of actions requires proper initiation and termination of each action sequence. The neural circuit that signals instructions to start and stop is now revealed.

PPAR? ligands are used to control diabetes, but their anti-diabetic actions are puzzling. Here the authors show that phosphorylation of PPAR? by cyclin-dependent kinase 5 (Cdk5) in mice is linked to obesity induced by high-fat feeding, and that inhibition of the effect in humans by the drug rosiglitazone is closely associated with its anti-diabetic effects. Several anti-diabetic PPAR? ligands directly inhibit the effect, and thus support a more normal non-diabetic pattern of gene expression.