The number of tumor-associated immune cells is correlated with poor prognosis in cancer patients. Reducing these cells in mouse models of breast cancer reduces tumor metastasis, indicating that tumor-immune interactions are critical for cancer progression.

In the July 8, 2013 issue of the Journal of Clinical Investigation, Shelley Earp and colleagues at the University of North Carolina a Chapel Hill demonstrate that removal of the protein MerTK from immune cells decreased tumor growth in mouse models of breast cancer, melanoma, and colon cancer. Loss of MerTK reduced the release of molecules associated with inflammation.

These findings suggest that drugs that inhibit MerTK may stimulate anti-tumor responses and could potentially have clinical benefit.