To achieve this goal, we propose to invite the 2,394 unaffected individuals from our multiplex family study, defined as those families with greater than or equal to 2 NPC. As a result of our recruitment efforts, we expect approximately 1,600 subjects to participate in an ear, nose, and throat (ENT) examination by an expert otolaryngologist to determine whether any of these individuals has occult or symptomatic NPC. We will correlate the three EBV antibody screening tests performed at the time of initial recruitment into our family study with NPC detection in the period between initial recruitment into the family study and the present study (median time between original EBV antibody testing and clinical evaluation = 5.5 years; range = less than 1 year - 10 years).