Suggested organisation of your literature review (remember to organise your literature review as inverted pyramid).
Your Literature review should explore and put into context (physiological/biochemical/pathological/genetic) relevance of the gene (and protein) that you have chosen to optimise for the purposes of amplification/detection.
For Example; (notice how each level below is/should be linked so the review ‘flows’ and that each levels is relevant to the one preceding and the one following.

1. Introduce the concept of Ageing/Senescence and the hazards/problems associated with these concepts (e.g. cost/treatment/burden on the state/life expectancy etc.,)
2. Associate these issues (A/S) with the diseases that your gene has been implicated e.g. Diabetes, Alzheimers, CVD, Inflammation, Cancer-types, Dementia, Inflammatory bowel disease etc.,
3. Include the types of indicators/processes (proteins/genes) that are known to be important in the progression/treatment of the above mentioned diseases e.g. amyloid plaques/atherosclerotic plaques/colonic polyps (examples of identifiable problems associated with your gene of interest, additionally introduce a range of other genes that have been found to be important in a particular disease process (ONE of which will be your specific gene/protein e.g. Ras, p16, p53, pRB, Myc, Gene/protein X (your protein/gene)
4. Describe protein/gene in relation to its genetic location, size of the gene, mRNA’s, where it is found in the cell (PM/Cytosol/Nucleus/Mitochondria or all areas and how is it transported throughout the cell?).
5. Expand on its importance in specific examples of diseases associated with ageing. Are there any animal knock-out models etc., What have researchers found/reported about the gene/mRNA/protein? For example …..
6. ….How does the gene/mRNA/protein work, what does it do in a cell/tissue/organ/organism and how is it specifically useful/deleterious to control the function of a cell? What other proteins are involved in its function. How is it expressed in different tissues and what does it do (protein) in different tissues? This section is primarily a MECHANISM of how the protein works/functions and should be the largest section of the review.
7. Are there any associated mutations within the gene which contribute to disease pathology. How many are there reported? How are the mutations been investigated? Where are the mutations and types of mutations that have been found – how does the mutations affect the function of the protein?
8. How is the protein/gene/mRNA detected? How is the detection process useful? (e.g. mechanism/drug discovery/treatment progression/prognosis/cure)
9. How useful is PCR for the detection of your gene compared to other diagnostic techniques. Can you use other types of methodological approaches to investigate its usefulness/problems?
10. Conclude on the usefulness of PCR detection and how will it contribute to the knowledge of your gene/protein.