A large team of researchers affiliated with a host of institutions in Europe and the U.S. has found a gene that plays a critical role in natural killer cell differentiation. In their paper published in the journal Science Immunology, the group describes their work involving transcriptional and epigenetic profiling of natural killer (NK) cells and what they learned about them. Timo Rückert and Chiara Romagnani with the German Rheumatism Research Centre have published a paper in the same journal issue outlining the role NK cells play in the immune system and the work done by the team on this new effort.