One of the characteristics of apoptotic cell death is the rapid removal of cell corpses, which are engulfed by macrophages or by non-professional phagocytes. This is because induction of cell apoptosis leads to the exposure of "eat me" signals on the cell surface before the late apoptotic event of cell lysis. Thus, apoptosis is a ‘clean’ process that does not normally lead to spillage of cell contents or to inflammation. Exposure of phosphatidylserine (PS) residues, which are normally asymmetrically distributed and restricted to the inner leaflet of the plasma membrane, has been identified as both an early event in apoptosis and a prerequisite for engulfment, as PS-containing liposomes can inhibit phagocytosis of apoptotic bodies. But what is the receptor for PS on phagocytic cells? Although several cell-surface molecules were proposed to contribute to the recognition of apoptotic cells, none of them seems to bind specifically to PS residues. An alternative model is that recognition is based on homophilic interactions, as exposure of PS on the surfaces of both apoptotic and phagocytic cells has recently been reported to be required for engulfment (Marguet et al., Nature Cell Biol. 1, 454–456; 1999). Now, in a recent issue of Nature (405, 85–90; 2000), Valerie Fadok and colleagues at the National Jewish Medical and Research Center in Denver, Colorado report the cloning of a PS receptor (PSR), using an antibody raised against activated macrophages, which they found to inhibit engulfment of apoptotic cells. PSR is expressed on macrophages and on certain epithelial cells and fibroblasts. Transfection of the gene encoding PSR confers T and B cells with the capacity to recognize and engulf apoptotic cells, which is inhibited by anti-PSR antibodies and by PS-containing liposomes. The picture shows a 3T3 fibroblast (labelled in green), transfected with complementary DNA encoding PSR, extending a protrusion and engulfing a Jurkat T cell that has been induced to die by ultraviolet irradiation (labelled in red). Interestingly, the PSR gene is conserved in Caenorhabditis elegans and Drosophila, indicating that, as is the case for the apoptotic programme, the mechanisms of engulfment may be evolutionarily conserved.