Introduction
‘Omic’ technologies adopt a holistic view of the
molecules that make up a cell, tissue or organism.
They are aimed primarily at the universal detection
of genes (genomics), mRNA (transcriptomics),
proteins (proteomics) and metabolites
(metabolomics) in a specific biological sample in a
non-targeted and non-biased manner. This can also
be referred to as high-dimensional biology; the
integration of these techniques is called systems
biology (Figure 1)(see Box 1 for a list of
definitions).1,2 The basic aspect of these approaches
is that a complex system can be understood more
thoroughly if considered as a whole. Systems
biology and omics experiments differ from
traditional studies, which are largely hypothesisdriven
or reductionist. By contrast, systems biology
experiments are hypothesis-generating, using
holistic approaches where no hypothesis is known
or prescribed but all data are acquired and analysed
to define a hypothesis that can be further tested.3
These strategies have many applications and much
potential. Omic technology can be applied not
only for the greater understanding of normal
physiological processes but also in disease
processes where they play a role in screening,
diagnosis and prognosis as well as aiding our
understanding of the aetiology of diseases. Omic
strategies lend themselves to biomarker discovery