We are thrilled to bring you this special review issue of Cell covering exciting frontiers in fundamental research and therapy that are transforming the ways in which we prevent, diagnose, and treat cancer.In thinking about the scope of the topics covered here, we were struck by an emerging theme of how cancer research has evolved from a tumor cell centric view to a more system-wide perspective that takes into account dynamic host responses, tumor microenvironment, and inter-cellular communication within the niche as well as with cells located afar.A global scourge like cancer needs collective efforts and viewpoints that cut across academia, industry, hospitals, public health and society at large. Cooperation and collaboration are the only way forward through the complexity that is cancer. We are committed to furthering the science and medicine through our journal and we dedicate this issue to those whose determined efforts have given us the reason for optimism and hope.