The powerful and wide-ranging genetic tools available in the laboratory mou
se make it the major experimental model for studying mammalian gene functio
n in vivo and modelling human disease traits. Large-scale random mutagenesi
s approaches, either gene-driven or phenotype-driven, promise to identify n
ew clinically relevant phenotypes and their associated genes. Development o
f appropriate tools for assessing clinical phenotypes in mice is a crucial
component of these endeavours, as is the establishment of the infrastructur
e for archiving and distribution of the growing mutant resource to the comm
unity. Integrated, multidisciplinary programs will be needed to fully explo
it the power of the mouse in molecular medicine.