Welcome to our fifth birthday issue! And what an amazing five years it has been for us and for immunology. Every discipline in the field has taken giant leaps forward, many of which have been discussed and debated in these pages since our launch in 2001.

In this slot in our first issue, we highlighted some of the challenges that lay ahead, such as understanding the interaction between the immune system and tumours, the ever-present need for more efficacious vaccines and the rise in the incidence of autoimmune diseases. In this birthday issue, we have articles that highlight advances made in each of these areas.

Laurence Zitvogel, Antoine Tesniere and Guido Kroemer (page 715) shed light on the surveillance strategies that are used by the immune system to detect tumours and on the mechanisms that are used by tumours to evade this detection. This Review is also part of our Article Series on Tumour immunology (http://www.nature.com/nri/series/tumourimmunology).

The generation of effective vaccines requires an understanding of how immunological memory is maintained. Andreas Radbruch and colleagues (page 741) provide an intriguing insight into how humoral memory is maintained through competition between plasmablasts and long-lived plasma cells for survival niches.

On page 751, Fu-Dong Shi and Luc Van Kaer discuss the role of natural killer cells in modulating autoreactive T-cell responses during the initiation of autoimmunity, a process that might have important implications for the development of novel therapies for autoimmune diseases.

Finally, we take this opportunity to extend our thanks to all of the authors who have contributed to the journal in the past five years, to the referees for their crucial input and, of course, to our readers.