After years of design, construction and testing, Jefferson Lab is installing a state-of-the-art Gas Electron Multiplier (GEM) tracking detector in one of its experimental areas. The detector tracks charged particles, such as those emitted by cancer cells tagged with a radiopharmaceutical or radiation beams used to target cancers. The extreme precision and fast readout technologies developed for the GEM detectors are now being applied to new state-of-the-art systems for nuclear medicine.