Doctor Thomas Insel points out that while the human genome project is largely complete, the real challenge lies in figuring out the function of each gene.
I remember when the human genome project was finished, I remember Sidney Brenner talking about it and saying, ‘This is terrific. We have a huge directory with all the addresses.’ But you know he said, 'You know, functionally what this is, is sort of like having the white pages of the phone book and what we really need now will be the yellow pages; we need to know where are all the plumbers, where are all the electricians, where are all the mechanics because when something goes wrong you want to go to the yellow pages. You don’t know necessarily where all the right candidates will be.’ I think an agenda for the field over the next several years will be actually developing those yellow pages, understanding how to provide the function and the interrelationships of all of the many parts of this genome. Of course, one of the things that most surprising for people in the last five years, and it’s been almost exactly 5 years since the publication of the human genome project. We thought we had a pretty good sense, even within the white pages, of all the names and all the addresses. We had about 23 thousand genes and where they were located. Of course, what we are now realizing is that there are lots of other elements within the genome that were not cataloged, that we’re still beginning to try to get some understanding of. All of these small RNAs, lots of other factors that are within all of the non-protein coding parts of the genome, and that’s going to be still a big challenge for us going forward.