It has long been recognized that tumors develop in part because they can evade the immune response, and that an optimal response to radiation requires an intact immune system. Immune checkpoint inhibitors and other new approaches to “awakening” the immune system to attack tumor cells have renewed interest in the interaction between radiation and the human immune system. SERPINB3 is thought to play an important role in regulating the immune response to self-antigens in autoimmune disease such as psoriasis, and autoimmune hepatitis, and recent work has implicated this protein in response to immune checkpoint therapy. We are interested in understanding the role of this protein and the SERPIN family of proteins in responding to the combination of immune therapy and radiation.