DNA microarray technology enables conducting experiments that measure RNA-transcript abundance (so called gene expression or expression degree) on a large scale of genomic sequences.
The starting point of this analysis is the so called gene expression matrix, where rows represent genes, columns represent experimental conditions (or samples), and the values at each position of the matrix characterize the expression level of the particular gene under the particular experimental condition.
MTECs also express a wide array of tissue restricted antigens (TRAs), so called "promiscuous gene expression" [15], [16], [17], some of which appear to be under the control of the AIRE transcription factor [18].
Arabesque, in literature, a contrived intricate pattern of verbal expression, so called by analogy with a decorative style in which flower, fruit, and sometimes animal outlines appear in elaborate patterns of interlaced lines.
With this antibody, yCD expression can now be monitored without interfering with its enzymatic function in GDEPT, ADEPT and other studies leading to the effect of the so called tumour amplified protein expression and targeting (TAPET) to localize in vitro and in vivo generation of the anticancer agent 5-FU [ 4].
In line with this possibility, expression of an extra class of small RNAs molecules involved in gene silencing, so called piRNA, is expressed specifically in spermatogenic cells [ 59].
In a first step, average within-class expression profiles, so called "centroids", are calculated for all sample classes.
Within the network, clusters of genes with similar expression patterns, so called modules, were then inferred using a clustering of the Topological Overlay Matrix (cutreeDynamic method; deepSplit = 2, minimal module size = 40, merging similar modules with parameter cut height = 0.2).
One of the important findings has been the classification of breast cancer into five subtypes (luminal A, luminal B, basal-like, ERBB2 enriched and normal-like) based on gene expression profiles of so called intrinsic genes [ 3, 4].
This might result in unreliable conclusions, because it has been demonstrated that the expression levels of so called "housekeeping genes" may vary considerably in different tissues, cell types or disease stages, particularly in clinical samples associated with malignant disease.
This subgroup shares many clinical and pathological features with the so called 'basal-like' subgroup according to gene expression profile analysis, first described by Perou et al. [ 10].
