A sequence logo for the transcriptional factor CTCF derived from binding site predictions from Ensembl on human chromosome 22. The height of the letters represents information content at each position. For example, if a particular nucleotide is always found at a given position, it will have the maximal height and information content, while if a position has all four nucleotides at equal frequencies, it will have a minimal height and no information content. One instance of a motif alignment is shown, which contains a variant at a high information position (boxed). The alternative allele at this position, A, results in a sequence more different from the motif represented by the PWM as measured by the motif score.