It is always attractive and seductive to describe any time in research as being one of transition, where the knowledge and insights of past work and the tools of our trade coalesce to fundamentally alter our concepts, our approaches, and our capacity to make progress. In truth, it is often easy to argue the case for such a transition, or even a transformation, but it is exceedingly difficult to prove. Whether we are at a profound transition in cancer research is an interesting question. The answer may be yes, but it may be more of a reflection of a long and ongoing transition rather than a unique inflection point. That said, I believe that we are at a point of emerging synthesis, new directions, and the emerging possibility that the science of cancer research could actually inform and transform the approach to cancer in patients and in populations. I am taking the liberty of a perspective to take a more conceptual overview of the types of questions being asked, to discuss how the enormous amount of knowledge gained over the past decades can be organized, and to point to the challenges (conceptual and technical) that lie ahead. I focus on the process of organization and synthesis because it is our emerging ability to bring a higher level of order to how we think about cancer, pulling together the flood of information garnered by thousands of researchers over decades, that, in part, provides a useful description of the beginning of the twenty-first century as a transition period in cancer research.

There is a bit of a paradox here. On the one hand, our emerging ability to synthesize information and to bring some simplifying order to cancer defines one aspect of this transition time, while on the other hand, as I will discuss, it is the need for and ability to begin to address cancer more directly in terms of its complexity that will characterize cancer research as we move forward. In the first, we are bringing together immense amounts of information gathered through a very successful reductionist approach to the study of cancer cells. In the sec-