The upstream regions of the genes are long studied for their ability to bind transcription factors.The regulation of gene expression is based on the fact that regulatory elements bind to these short sequences and modulate gene expression.
                  

                   Recently, Ambrosini et. al.(2018) have developed an algorithm by use of which one can span the entire genome sequence present on the server for a match to a user supplied weight matrix model.
 

                  The source code is available at  https://sourceforge.net/projects/pwmscan and the web server is available at http://ccg.vital-it.ch/pwmscan.

Reference:
Ambrosini et. al.(2018)PWMScan:a fast tool for scanning entire genomes with a position-specific weight matrix.Bioinformatics 34(14):2483-2484