Human–mouse comparative map. A comparative map of the human genome and the homologous murine regions. An ideogram of the human karyotype is shown, with murine homology regions indicated to the right of each map. Solid homology regions, defined by numerous conserved markers that have been mapped with good accuracy in both species, are indicated by solid bars. Hatched bars denote regions to which fewer markers have been mapped and for which human and/or mouse map assignments have been established with less accuracy. Asterisks (*) indicate the approximate positions of single markers that have been mapped to both species—several asterisks observed adjacent to a human band indicate that a small number of markers have been mapped to that region, but those markers are known to map close together over a limited interval and/or are mapped at low levels of accuracy. Each murine homology region is color-coded to correspond to specific mouse chromosomes (see also Fig. 2). The cytogenetic positions determined for several human diseases, represented by locus symbols, are indicated to theleft of each human map. A selection of locus symbols corresponding to mouse mutations that are known to map within a particular homology region are included at far right of the map in italics. An asterisk denotes the human gene or mouse mutant has been cloned; underlining indicates that human diseases and murine model, aligned in parallel positions on the map, are known to be associated with orthologous genes. For reference information, see Fig.2.