The origin of the Bioinformatics Group of the Genetics Core (former LGD Core) lies in the work of LGD scientists in identifying genetic factors, notably CCR5-?32 and HLA Class I alleles, that profoundly influence HIV infection and AIDS progression. Over 12 succeeding years we have refined and extended the genetic and epidemiological skills to advance the understanding of genetic influence on complex disease. The database, analytical, and genotyping support activities of the BI Core are tuned to the particular needs of the Genetics Core, and of the CCR scientists that use Genetics Core resources in their research. The emphasis on AIDS genetic association research has given us specialized knowledge of AIDS association analysis, along with deep knowledge of the clinical data from our cohorts. We have more recently generalized this knowledge and skill to the study of other complex diseases, and have added skills in areas of genomics critical to the understanding of complex disease.