Approximately 30,000 genes are functional while other genes in the genome are not expressed. Expressed genes are necessary for proper functioning of all the systems present in humans. Therefore, an approach towards the understanding of expressed genes (i.e. proteins), which is termed as the "proteome" is helpful in understanding all life processes.

Proteomics would be very helpful in detailed analyses of diseased states and suitable treatment protocols. Most diseases are detected late, which usually results in less effective treatment. Proteomics would be the best tool for early disease detection and thus accelerating drug development at a higher pace with respect to their dosage and toxicity.

There are various methods of disease diagnosis--however, the application of proteomics in disease diagnosis has been given priority due to its ability of identifying important disease markers accurately. This is helpful for faster disease diagnosis, as well as effective therapeutics. This method is based on the protein profiling of diseased and normal tissues/cells and their comparative analyses. It can be directly used by taking biological samples in very small amounts and giving higher throughput with respect to any other known techniques.

An overview of important applications of proteomics in disease diagnosis and therapeutics include: Cancer diagnosis and therapeutics; Diagnosis of infectious diseases and treatment; Applications to prognosis; and finally Drug Development.