The Top 20 k-mers according to a 6-mer kernel SVM in all six organisms.

The highest ranked k-mers contribute the most to classifying a region as a non-methylated island. K-mers containing more than one A or T nucleotide are in bold. A and T nucleotides are almost completely absent from high scoring 6-mers in warm-blooded organisms, while nearly every high scoring 6-mer contains an A or T in cold-blooded organisms.