Erratum to: ‘The orientation of transcription factor binding site motifs in gene promoter regions: does it matter?’

Unfortunately, the original version of this article [1] contained an error. Equation number two was missing a “–“ (a minus) sign before the sum symbol. The correct equation has been included here. This correction concerns the notation only. All computations using this equation were done correctly.

$$P{E}_m=-{\displaystyle {\sum }_i{p}_i\mathit{log}\left(p_i\right)}\text{,}$$ 2