On June 26, 2000, President Bill Clinton and Prime Minister Tony Blair jointly announced that researchers had completed the first draft of the human genome, a map that spelled out the three billion letters of the genetic code. "Without a doubt, this is the most important, most wondrous map ever produced by humankind," said Clinton. Blair was equally effusive. "Let us be in no doubt about what we are witnessing today-a revolution in medical science whose implications far surpass even the discovery of antibiotics, the first great technological triumph of the 21st century," said Blair.

But neither leader uttered a word that would soon take over the allure and promise that "genome" once enjoyed everywhere from the White House to Wall Street: "proteome."

Just as genomics is the attempt to decipher all of the genes in an organism, proteomics, in its simplest definition, aims to uncover all of the proteins and their functions. Since genes are simply the blueprints for proteins, which in turn are the main players in most of the body's functions, it's a logical progression. Indeed, there is no mistaking what proteomics promises: a revolution in medical science with implications that far surpass those of genomics.

Sounding an awful lot like the genomics gurus of yesteryear, proponents of proteomics declare that a "global understanding" of proteins will reveal the underlying mechanisms of disease, leading drugmakers to treatments that ablate causes rather than mask symptoms. Companies will discover a bounty of natural proteins that can serve as injectable drugs, the advocates assure, as well as an abundance of new protein targets for the "small-molecule" pills that are the cornerstone of the pharmaceutical industry. Side effects will plummet as the precision of treatments increases. A finer appreciation of the differences between the proteomes of individuals will allow doctors to tailor treatments to specific populations. And as new technologies emerge-your entire proteome on a chip?-medicine will advance in ways that even the most farsighted visionaries cannot imagine.