The innate immune response, which is responsible for eliminating infectious pathogens from the body, also provides the first line of defense against endogenously derived cancer cells. Currently, the mechanisms that trigger the innate immune process in cancer are unclear. Using a Drosophila model of tumorigenesis, José Pastor-Pareja and colleagues found that tumorigenesis recruits Drosophila immune cells, known as hemocytes, to areas of breaks in the basement membranes surrounding tumor cells, and stimulates an increase in circulating hemocytes resulting in suppressed tumor growth. Using an aseptic wounding technique, they show that tissue damage can activate JNK signaling and induce expression of JAK/STAT-activating cytokines. This fly study demonstrates a conserved and important role for the innate immune system in recognizing the tissue damage associated with tumor formation and suppressing tumor growth.

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