Heatmap visualization of biclusters. a) Typical heatmap, with bright colors representing the lowest or highest transcription levels. b) A section of the heatmap in a), after reordering the rows and columns in such a way as to put those corresponding to an identified bicluster first. c) Two non-overlapped biclusters can be seen on the diagonal of the matrix. More non-overlapped biclusters could be added, but if they overlap, representation becomes difficult, or even geometrically impossible without replication of rows and/or columns.