(CNN) -- Much of the marvel of medicine has to do with discovery. Mapping the human genome, the complete sequence of DNA, gave scientists a blueprint for building a person, making it the No. 1 medical story, according to a distinguished panel CNN gathered to rank the top 25 medical stories of the past quarter-century. Two men from two separate groups -- Francis Collins of the National Institutes of Health and Craig Venter of Celera Genomics Inc., a pharmaceutical-development company -- worked independently to discover the sequence of the human genome and identify the genes that it contains. This research led to the development of gene-based "designer drugs" that can fight specific diseased or damaged cells. One such drug is Gleevec, which has proven effective in fighting a form of leukaemia. Other drugs that can target various forms of cancer and other diseases could soon be on the way now that scientists know what to look for. "By 2015, we will see the beginnings of a real transformation in the therapeutics of medicine, which by 2020 will have touched virtually every disorder," Collins said. "And the drugs that we give in 2020 will for the most part be those that were based on the understanding of the genome, and the things that we use today will be relegated to the dust bin." Continued study on other potential scientific breakthroughs, like disease-curing stem cells (No. 2), cloning (No. 3), gene therapy (No. 14), and reproductive surgery (No. 20) may not move as quickly, as they are hampered by controversy despite signs of success. From creating new life to preserving existing lives, a revolution in life-saving procedures has included live liver transplants (No. 5), first performed in 1989, and the self-contained artificial heart (No. 6), which debuted in 2001. http://www.cnn.com/2005/HEALTH/01/31/cnn25.top.medical/