The draft human genome sequence, announced with much fanfare in 2000, promised great insights into human biology, medicine and evolution. In this special, Nature asks whether the sequence has delivered the insights that were anticipated, and what lessons have been learned from the first post-genome decade. Human genetics in 2010 looks infinitely more complex, and questions about how to make sense of the explosion in biological data are only becoming more pressing.

Up to 94% of human genes can generate different products.