DNA microarray technology is a method for probing the
expression of thousands of genes under a variety of experimental
conditions. Gene expression data obtained from microarray
experiments has inspired several applications, including the
identification of differentially expressed genes for molecular
studies or drug therapy response [19], identification of unknown
effects of a specific therapy [14], and the creation of
classification systems for improved cancer diagnosis [15]. Traditional
data mining algorithms such as k-means and agglomerative
hierarchical clusterings have proven useful for identifying
biologically relevant clusters of tissue samples/experimental
conditions and genes [7]. See [6] for an empirical study of
advanced clustering algorithms for microarray data analysis.