The analysis of regulatory regions in genome sequences is strongly based on the 
detection of potential transcription factor binding sites. The preferred models 
for representation of transcription factor binding specificity have been termed 
position-specific scoring matrices. JASPAR is an open-access database of 
annotated, high-quality, matrix-based transcription factor binding site profiles 
for multicellular eukaryotes. The profiles were derived exclusively from sets of 
nucleotide sequences experimentally demonstrated to bind transcription factors. 
The database is complemented by a web interface for browsing, searching and 
subset selection, an online sequence analysis utility and a suite of programming 
tools for genome-wide and comparative genomic analysis of regulatory regions. 
JASPAR is available at http://jaspar. cgb.ki.se.