On the 15th February 2001 a draft version of the complete human genome was completed.  This draft version was far from perfect but was still a major milestone in the biological world. So, what has come from this? What have we learned so far and what is yet to come?
The human genome contains approximately 20,000 – 25,000 genes. Genes encode proteins that perform most life functions. But, only 2% of the human genome is made up of genes. The function of many genes and the vast remainder of sequences in the human genome are yet to be fully understood. 
In an attempt to understand all that, an international research project was set up in 1990. The project also included non-human organisms such as E. coli, the fruit fly, and a lab mouse! Ahead of schedule, the draft genome was published in 2001 and by the end of 2003 most of the human genome sequencing was complete. 
Expression to understanding…
So what has cracking the human genome done for the world of biology? There is no short answer to this question. This project has opened the door to lots of intense and interesting research. It has enabled the transformation of fragmented information into whole pictures of biological structures and shed light on biological functions. Some of them include:
- Mapping of evolutionary conservation
- Determination of the chromatin structure
- Information on genetic variation
- Medicine – association with inherited diseases and cancer
Even though the genome is billed as being complete, some regions of each chromosome within the genome remain unsequenced  and understanding the functions of all the genes and their regulation is not yet complete.
Two such regions include:
- Centromeres – extremely repetitive DNA sequences that are difficult to sequence with current technology.
- Telomeres – ends of the chromosomes again, highly repetitive and sequencing is hindered by current technology
Genome sequencing must be made relatively simple and cheap for it to be routinely used as a biomedical tool. There is much value in creating extensive gene catalogues. It will be a daunting task but this will shed light on biological functions. 
For example, genetic studies of tens of thousands of patients for most common diseases and functional studies to characterize the genes and pathways, to construct animal models that mimic human physiology will immensely aid our understanding of human diseases.
Private companies such as 23andMe (https://www.23andme.com/) and deCODE genetics (http://www.decode.com/) have already started this trend, but safety and risks around making this accessible to public is still under hot debate.
So when all this is taken into account, it seems that more questions have come from the HGP. The holy grail of identifying the genes within the human genome alone has not provided all the answers. But if the results and knowledge gained in the past ten years have proven anything, it’s that the HGP’s teenage years will be nothing but eventful.
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 Lander, Nature, 2011, 470, 187
4 Mardis, Nature, 2011, 470, 198
5 Green et al., Nature, 2011, 470, 204