Proteomics is the study of proteomes on a vast scale. A proteome is a collection of proteins made by a living organism, system, or biological milieu. We can talk about a species' proteome (for example, Homo sapiens) or an organ's proteome (For example, the liver). The proteome is dynamic, varying from cell to cell and changing throughout time. The proteome reflects the underlying transcriptome to some extent. However, in addition to the expression level of the relevant gene, many other factors influence protein activity (which is generally measured by the response rate of the processes in which the protein is engaged). It is currently reliant on decades of technological and instrumental advancements. Advances in mass spectrometry (MS) technology, protein fractionation techniques, bioinformatics, and other fields have all contributed to these advancements.