E-Mail Not all cancerous tumors are created equal. Some tumors, known as "hot" tumors, show signs of inflammation, which means they are infiltrated with T cells working to fight the cancer. Those tumors are easier to treat, as immunotherapy drugs can then amp up the immune response. "Cold" tumors, on the other hand, have no T-cell infiltration, which means the immune system is not stepping in to help. With these tumors, immunotherapy is of little use. It's the latter type of tumor that researchers Michael Knitz and radiation oncologist and University of Colorado Cancer Center member Sana Karam, MD, PhD, address in new research published this week in the