A novel pathway by which metastatic breast cancer cells dampen the body’s immune responses to thrive in bone is published online this week in Nature Medicine.

Belinda Parker and colleagues show that human bone metastasis have decreased amounts of Irf7, a master regulator of interferon responses that typically provide an enhanced immune response, and of its target genes. Deregulation of Irf7 by tumor cells accelerates bone metastasis by invoking the pro-tumorigenic help of myeloid-derived suppressor cells while keeping other anti-tumor immune effectors at bay.

The findings provide a new perspective on how metastatic tumors subvert innate immune responses and suggest the potential benefit of antimetastatic therapies targeting IFN signaling in people with breast cancer.