To construct an infrastructure for genome-wide association studies of common diseases or drug sensitivities, we have been systematically exploring common variants by resequencing genomic regions containing genes in DNA from 24 Japanese individuals. We have analyzed a total of 154 Mb, corresponding to approximately 5% of the human genome, and so far have identified 174,269 single-nucleotide polymorphisms and 16,293 insertion/deletion polymorphisms within gene regions, i.e., one polymorphism in 807 bp on average. Our data are freely available via our web site (http://snp.ims.u-tokyo.ac.jp) and will facilitate studies to identify genes associated with susceptibility to common diseases and genes involved in sensitivity to therapeutic drugs.