Nature Immunology doi:10.1038/ni.1787 (2009)

A master gene turns blood stem cells into the 'natural killer' immune cells that fight viral infections and help stave off cancer.

When Hugh Brady at Imperial College London and his colleagues created knockout mice lacking the gene for a particular gene-regulatory protein, E4bp4, the mice made the other immune system cells — B cells and T cells — but no killer cells. Adding back the gene for E4bp4 to blood stem cells from E4bp4-deficient mice enabled these cells to produce natural killer cells again.

The mouse strain lacking E4bp4 will help in investigating the role of natural killer cells in disease prevention and in finding drugs that boost their production, the authors say.