Granulysin, formerly known as NKG5 or Lymphokine LAG-2, is a membrane-lytic protein that is expressed in granules of natural killer and activated cytotoxic T cells. It exhibits cytolytic activity against intracellular or extracellular microbes and also tumors, either alone or in synergy with Perforin. IL-15 is necessary and sufficient for Granulysin release from CD8+ T cells. Granulysin promotes chemotaxis and increases production of chemokines by monocytic cells as well as target cell lysis. It binds and disrupts microbial membranes through charge interactions.