The present protocol will use a new PET ligand [(11)C]ER176 to 1) perform an initial whole-body scan after [(11)C]ER176 injection in a single healthy volunteer to confirm wide-spread distribution of radioactivity to different body organs (Phase 0); 2) perform kinetic brain scans in healthy volunteers of 3 different genotypes, with about half of these volunteers undergoing lung scans in the same session (Phase 1), and; 3) perform whole-body imaging in healthy volunteers (Phase 2).