Alleles, Antigens, CD, B-Lymphocytes, Chromosome Mapping, Chromosomes, Human, Female, Flow Cytometry, Genes, bcl-2, Humans, Killer Cells, Natural, Linkage Disequilibrium, Lymphocyte Count, Lymphocyte Subsets, Male, Phenotype, Quantitative Trait, Heritable, T-Lymphocytes, Utah