A Population-based case-control study is proposed to examine the relationship between HLA type and nasopharyngeal carcinoma (NPC). This study is dissertation research that takes advantage of an opportunity offered by the existence of an ongoing multi-centered questionnaire-based study of environmental and lifestyle risk factors for NPC. The proposed study would be the largest such study that has ever been carried out with its focus on a low-incidence Caucasian population. Its goals are to investigate i) whether NPC cases with high-risk HLA types have distinctive profiles of antibody response to Epstein-Barr virus (EBV), and agent of possible etiologic significance in the disease. blood samples from a subset of subjects of White race (113 cases, 113 controls) participating in the on-going study will be obtained by visiting subjects at home or a location of their choice. HLA typing, Western blot analysis of patterns of anti-EBV antibodies, data processing and analysis will be performed at central facilities in Seattle. Both stratified and multivariate analysis will be used to evaluate the association between HLA type and NPC.