Figure 2.

Phenotype discrimination with gene triples. Expression pattern of normal and cancer samples, separated by the vertical line. There are two latent subclasses among the cancer samples, represented by the two relative orderings between gene 1 and gene 2. Whereas the normal and diseased samples cannot be separated by this relative ordering alone, refining it by a third gene identifies the normal samples as those for which the pivot gene is the most expressed among the three.