One of the main reasons cancer remains difficult to treat is that cancer cells have developed a multitude of mechanisms that allow them to evade destruction by the immune system. One of these escape mechanisms involves a type of immune cell called myeloid-derived suppressor cells (MDSCs). A recent study led by Sharon Evans, PhD, Professor of Oncology and Immunology at Roswell Park Cancer Institute, provides new insight into how MDSCs enable tumor cells to circumvent immune attack and offer the potential for improving cancer immunotherapy. The research has been published today in the journal eLife.