From the outside, the Counterterrorism Education Learning Lab’s exhibit space in downtown Denver has sat quiet for more than four years. But behind the scenes, the nonprofit institute, known as The CELL, has been at work updating its offerings to provide an interactive experience geared toward current security threats. The exhibit is focused on the factors that drive domestic and international terrorism and the impact of those threats on global security — along with educating visitors on what everyday people can do to prevent terrorist acts in their communities. This week, the results of those efforts will be unveiled when The CELL, 99 W.