Complete genome sequences are providing a framework to allow the investigat
ion of biological processes by the use of comprehensive approaches. Genome
analysis also is having a dramatic impact on medicine through its identific
ation of genes and mutations involved in disease and the elucidation of ent
ire microbial gene sets. Studies of the sequences of model organisms, such
as that of the nematode worm Caenorhabditis elegans, are providing extraord
inary insights into development and differentiation that aid the study of t
hese processes in humans. The field of functional genomics seeks to devise
and apply technologies that take advantage of the growing body of sequence
information to analyze the full complement of genes and proteins encoded by
an organism.