Subword Structure of Effective Subword-unique Motifs. A subword tree illustrating the makeup of the subword-unique motifs associated with antisense effectiveness. A motif is linked with an arrow to another if the motif at the tail of the arrow is a submotif of the one at the head that differs only by the addition of one base to the beginning or the end. For example, "CC" would be at the tail of an arrow connecting it to either "CCG" or "GCC", but there would be no arrow connecting it to "CGC" or "GGCC". For motifs associate with antisense effectiveness, the majority of significant motifs are linked in a tree with "C" as the root node.