Microarrays for simultaneous measurement of redundancy of RNA species are widely used for
fundamental biology research. They are also tested for their use in personalized medicine in
disease diagnosis and prognosis. From the pointof mathematical statistics, the invention of
microarray technology in the mid-1990s allowed the simultaneous monitoring of the expression
levels of thousands of genes. Microarrays for simultaneous measurement of redundancy
of RNA species are used in fundamental biology as well as in medical research. Microarray
may be considered as an observation of very high dimensionality equal to the number of
expression levels. There arise some needs to develop new statistical methods to handle the
data of such large dimensionality, especially connected to the fact of small number of observations
(which is the number of arrays). Because of the small number of observations the standard
asymptotic methods of multivariate statistical analysis appear to be inapplicable.