Further, discovering GRNs using microarray data has some
additional inherent difficulties. Various stages are used to regulate
gene expression, including DNA transcription, RNA processing
and transport, RNA translation, and post-translational adjustment
of proteins. The biological activity in the first of these stages is
captured by DNA microarrays while the changes in mRNA
transcript abundance do not necessarily reflect the regulation in the
later stages. More experimental tests are therefore required for
determining the validity of genetic interactions predicted by
network models [10].