Macrophages recognize and remove dead cells throughout the body but they also sometimes actively induce apoptosis. Richard Lang and co-workers have been investigating this phenomenon during programmed vascular regression of the hyaloid vessels in the developing mouse eye. They now report that in this system macrophages play an obligatory role in a cell death switch mediated by angiopoietin 2 (Ang2; see p. 4449). Using genetic experiments and the intra-ocular injection of various factors, the researchers show that during hyaloid vessel regression,Ang2 (probably produced by the pericytes that coat small blood vessels) has two effects: it suppresses Akt-mediated cell survival signalling in the vascular endothelial cells (VECs) and it stimulates the production of Wnt7b by macrophages. Wnt7b, the researchers report, stimulates VECs to enter the cell cycle where they die in G1 phase because of the absence of survival signals. This mechanism, the researchers suggest, ensures that macrophages are on hand to sweep up the debris when cell death occurs.