[i] The first row counts all distinct matches in the target; the second row gives the number of queries with a valid match; the third row counts how many of the 4241 queries had a unique match within our threshold (score <10⁻²⁵ and percent identity over 40%); and the last row are all those unique matches that have at least 50 bases upstream that do not overlap coding sequence on either strand. There are 2127 E. coli genes that have orthologous upstream region in at least one organism, and 768 genes with an orthologue in all four species.