Although many research works have been published regarding
GRNs, there is still much confusion in the current literature and it
is important to start the present work with a definition that is as
unambiguous as possible while regrouping the common GRNs
descriptive characteristics chosen by different researchers. As a
result, it is fundamental to first differentiate between GRNs and
other network models for gene regulation such as transcriptional
regulatory networks (TRNs) and co-expression networks (CENs),
for instance [11]. Furthermore, the work concentrates on gene
expression profiles and on the biological knowledge available in
public databases and in large datasets. These are used to estimate
possible GRNs with biological significance within the larger
framework of systems biology [12], [13].