Abstract Looking beyond tumor angiogenesis, the past decade has witnessed a fundamental change of paradigm with the discovery that the vascular endothelium does not just respond to exogenous cytokines, but exerts active “angiocrine” gatekeeper roles, controlling their microenvironment in an instructive manner. While vascular niches host disseminated cancer cells and promote their stemness, endothelial cell–derived angiocrine signals orchestrate a favorable immune milieu to facilitate metastatic growth. Here, we discuss recent advances in the field of tumor microenvironment research and propose angiocrine signals as promising targets of future mechanism-driven antimetastatic therapies, which may prove useful to synergistically combine with chemotherapy and immunotherapy.