The parallel lives of angiogenesis and immunosuppression: cancer and other tales

This article discusses the evidence in support of the simultaneous activation of angiogenesis and immunosuppression in a homeostatic tissue repair programme and proposes that these normal biological processes are co-opted by tumours to enhance tumour growth. Emerging evidence indicates that angiogenesis and immunosuppression frequently occur simultaneously in response to diverse stimuli. Here, we describe a fundamental biological programme that involves the activation of both angiogenesis and immunosuppressive responses, often through the same cell types or soluble factors. We suggest that the initiation of these responses is part of a physiological and homeostatic tissue repair programme, which can be co-opted in pathological states, notably by tumours. This view can help to devise new cancer therapies and may have implications for aseptic tissue injury, pathogen-mediated tissue destruction, chronic inflammation and even reproduction.