I (Elaine Bell) was privileged to join Nature Publishing Group in January 2001 as the launch Editor for Nature Reviews Immunology, and in October 2001, following a nine-month gestation, we published our first issue — and yes, it felt very similar to one's thoughts on giving birth: ooh that was hard, I won't do it again in a hurry!

In 2001, the Toll-like receptors were becoming established as key sensors and initiators of innate immune responses. Indeed, the Review by Ruslan Medzhitov published in our second issue has now accumulated 1,115 citations, reflecting the ongoing interest in this key topic, which is highly relevant to how we treat immune-mediated diseases. Regulatory T cells were also a key topic and, although we now understand a lot more about these cells than in 2001, many investigators would agree that the title of a Review by Ethan Shevach published in our ninth issue 'CD4+CD25+ suppressor T cells: more questions than answers' is still relevant for the field. Since 2001, the T helper 1 (TH1)/TH2 cell paradigm has been challenged by the ever increasing number of T cell subsets, including TH17 cells and T follicular helper cells, and the community has become more focused on translational immunology.

So, the field has moved on since 2001, and it is now time for me to do so as well. By the time you read this, I will have handed the reins to a new Chief Editor. I have thoroughly enjoyed my time as Chief Editor of Nature Reviews Immunology and I am very proud of what the team has achieved since its launch. I have no doubt that the journal will go from strength to strength and will continue to provide accessible, in-depth coverage of immunology.