"The failure to bring about major advances in cancer care over the past decades points to the need for a revolution in our view of cancer as a disease caused by a lack of growth control in malignant cells. We propose that a tumor should be considered a communicating organ made of multiple cell types that collectively evolve into a clinically manifested and deadly disease. With this proposition follows that targeting of communication within tumors to attenuate the support from the stroma is the only viable strategy to achieve long term therapeutic benefit. Our research addresses the need to study the cellular context of cancer with a higher resolution. The general aim of the proposed work is to identify subsets of different cell types within the tumor stroma that hold utility as therapeutic targets and biomarkers. The work will be performed through a set of experiments bridging basic biology, pre-clinical studies and molecular oncology.The specific aims are:1) Identification of cellular subsets of the tumor vasculature2) Investigation of the therapeutic utility of cellular subsets of the tumor vasculature3) Exploration of the potential of cellular subsets of the tumor vasculature as biomarkersThe aims of the study will be pursued through a series of methodological refinements. Firstly, identification of novel components of tumors will be achieved by the assembly of a mouse genetic tool box enabling isolation, lineage tracing and functional studies. Secondly, single cell transcriptome sequencing will be performed to identify cellular subsets using materials from both mouse and man. Thirdly, the utility as therapeutic targets of the new cellular subsets will be assessed using a live imaging approach. Fourthly, the clinical significance of the new cellular subsets will be investigated using exclusive patient materials.Taken together, the information provided by our studies will enable us to take cancer therapy into a new era of personalized medicine."