GNPX 2017 Annual Report

8 Additionally, under stress conditions, such as oncogenic stress, cells go through a regulated process of programmed cell death, or cellular suicide, called apoptosis, in order to control cell development and replication. The TUSC2 protein interacts via various apoptotic signaling pathways to stimulate programmed cell death via the release of caspases, enzymes that play a significant role in apoptosis. Pan-Kinase Inhibition by TUSC2 Stimulation of Apoptotic Signaling by TUSC2 Cancer and the Immune Response When functioning normally, the body’s immune system recognizes and destroys cancer cells, as well as other mutated cells and foreign bodies. As cancer develops over time, some mutations in cancer cells enable them to inhibit immune mechanisms, thus allowing the cancer cells to escape detection and destruction by the immune system and leading to the cancer’s “immune tolerance.” Therapies are being developed to allow patients to overcome this immune tolerance, some by stimulating the natural immune response and others by removing the inhibitions on the immune response created by the cancer. For example, PD-1 is a protein found on certain types of T cells, which are part of the immune system. Because PD-1 prevents T cells from attacking other cells, including in some cases cancer cells, inhibiting PD-L1 receptors, a process called PD-1 checkpoint inhibition, can facilitate the immune response to cancer.