Natural Killer cells are part of the body’s front line defence against infection and cancer. The September and October issues of Immunology feature several reviews discussing recent advances in our understanding of NK cell activation, killing, and disease.

Due to the potent nature of NK cells their activation must be tightly regulated; Stern-Ginossar & Mandelboim discuss mechanisms controlling the expression of the activating receptor NKG2D.

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Following activation, NK cell killing is mediated by the release of cytotoxic molecules from secretory lysosomes stored within the cell. Topham & Hewitt discuss what we currently know about the molecular mechanisms for NK cell secretory lysosome exocytosis, and the immunological consequences of defects within this machinery.