The number of proteins produced by the 30,000-40,000 genes of the human genome is estimated to be three or four orders of magnitude higher. Proteomics is a rapidly developing science. In principle, two main areas in the field of proteomics have been developed, each of them having its pros and cons. These fields are profiling and functional proteomics. The aim of the proteomic profiling is to describe and index the whole set of proteins of a biological sample, which could be an organism, an organ, or a cell, or parts there of like individual's tissue or organelles. In our understanding, both types of proteomics (profiling and functional) are valuable tools complementing other biological methodologies.