We'll end as we began, shall we? We started 2008 by publishing the first two of our articles in the Hypoxia and metabolism series, and we conclude 2008 with our final article: a Timeline on the impact of O2 availability on human cancer, by Jessica Bertout, Shetal Patel and M. Celeste Simon on page 967.

Looking back at the history of a research field is often informative, especially for researchers who are new to the discipline. It enables them to understand some of the prevailing problems that are associated with the field and the ways in which they have previously been tackled. Coincidentally, our second Timeline article in this issue reviews an oncogene that has emerging ties to tumour metabolism and hypoxia — MYC. Studying MYC is both a rewarding and a frustrating pastime, as Natalie Meyer and Linda Z. Penn describe on page 976. This article is also part of our ongoing series of articles on this infamous gene. To represent the research areas that have grown from the initial studies on MYC and how they are interconnected, these authors chose to use a tree-based structure. The ever more detailed branching of the twigs and leaves at the tips of the tree illustrate the complexity with which we need to view the function of MYC in cancer biology today. As our series on MYC is showing, and our series on Hypoxia and metabolism has shown, the route to new cancer therapeutics needs a clear view of the wood from the trees.

We would also like to end the year by thanking all of our authors, referees and Research highlights advisors for taking the time to write and work with us, and for helping us keep Nature Reviews Cancer at the top of the reviews in oncology tree!