Death associated protein 1 (DAP-1) is a 15-kDa protein that functions as a positive mediator of cell death initiated by interferon (IFN-) gamma (1,2). DAP-1 is proline rich and possesses one SH3 binding motif, as well as several consensus protein kinase phosphorylation sites (1). It is localized to the cytoplasm, but the detailed mechanism of its pro-apoptotic function is unclear. DAP-1 and DAP kinase, a unique, 160-kDa calmodulin-dependent serine/threonine kinase, are both unique candidates for positive mediators of programmed cell death induced by IFN-gamma (3).