Since ten years, there is an extensive search for association between antigens of the major histocompatibility system HLA and malignant diseases. Data show only weak associations with Hodgkin disease and acute lymphocyte leukemia. For studies of a variety of solid tumours the difference between patients and controls do not attain statistical significance, except for nasopharyngeal carcinoma. According to the gene frequency variations in populations and the ethnic differences in some cancers, inter-population studies are possible. Significant geographic associations between some cancers and HLA antigens have been found. They give evidence for a genetic background of susceptibility or resistance to cancer.