A cross-discipline team of School of Medicine and Department of Medicine researchers have published, “Breast cancer-derived GM-CSF regulates arginase 1 in myeloid cells to promote an immunosuppressive microenvironment” in The Journal of Clinical Investigation. The team of researchers found that breast cancer cells secrete lactic acid and a signaling protein, GM-CSF. GM-CSF in the acidic environment causes immune cells to express the enzyme arginase-1, which inhibits T-cells from attacking cancer cells. When the GM-CSF signal was blocked, findings showed increased effectiveness of immunotherapy and decreased tumor growth. Read the full study here.