Contains mapped large DNA fragments that span eight human chromosomes at ∼1-Mb resolution. GenMapDB is useful in a wide range of applications from microarray-based gene mapping to identification of chromosomal mutations. It contains information about759 mapped clones. It allows users to retrieve clones that map to an entire chromosome or a region of a chromosome. The DNA in the clones of the final map will represent ∼600 Mb or 20% of the entire human genome.