Scientists are searching uncharted territory as they slowly but relentlessly delve into the hidden chemical world that exists within the living cell. Discoveries are coming thick and fast, and each offers great promise in the effort to overcome disease.
Yet if ever the hackneyed Pandora's Box analogy was appropriate, then surely it is apt in the case of leading-edge medical research. Our technical understanding of the cell's inner processes is rushing ahead of social and ethical controls to oversee the application of these discoveries.
Human cloning, genetic engineering, growing organs in test tubes and the possibility of "designer babies" have popped out of the box, and who knows what is to follow. The question is whether we can control what has emerged so far, never mind future discoveries. Will we be able to prevent abuses of a technology that otherwise offers unparalleled promise in terms of curing disease, reducing suffering and improving the quality of life.
The power of advanced medical technology is undoubted. In general terms, it includes our rudimentary understanding of the human genome, the DNA blueprint of life inside each cell; biochemistry which tells us about reactions as the cell lives and responds to its environment; and proteomics, how key biochemicals called proteins interact.
All are linked in a complex web of life that cannot be separated but can be studied in detail as parts of a whole. And as we learn, so follow new treatments and new ways of tackling illness.
Some involve drugs, others involve replacing missing or damaged proteins with working copies. The goal in certain illnesses, such as cystic fibrosis, Ireland's most common genetic disease, or diabetes, is to introduce replacement bits of DNA - new genes that will deliver a permanent repair to non-working ones.
So where is the research taking us? Dr Cliona O'Farrelly, research director of the Education and Research Centre at St Vincent's Hospital in Dublin, is enthusiastic about where we are going.
One startling new area is the use of progenitor cells, called stem cells, to provide replacement tissues. These special cells are "undifferentiated", in that they haven't committed to becoming say a liver or a lung or skin cell. Scientists are studying what makes them change in the hope of controlling the differentiation process and so dictating what a stem cell will become.
Embryos are a rich but controversial source of stem cells. Researchers have shown that harvested stem cells can be converted into brain tissue, which might help patients with Parkinson's Disease.
Dr O'Farrelly's team is searching for adult stem cells, which are being found in many organs. These are being grown into blood-producing and blood vessel-related cells. In the future, the goal would be to "grow them into three-dimensional structures". The result will be off-the-shelf organ replacements, grown from the person's own tissue, which would mean there would be no risk of rejection.
"Within five years, you will be able to grow your own organs in a test tube," says Prof Luke O'Neill, director of the Biotechnology Institute at Trinity College Dublin.
The first treatment is likely to be for diabetes, a disease where the body loses insulin-producing cells. A replacement pancreas would have these cells. Next will come replacement brain tissues for Parkinson's and Alzheimer's diseases.
Prof O'Neill believes the ethical difficulties of having to use either foetal cells or cells recovered from fertilised eggs grown in vitro will be reduced because stem cells are being found in adult tissues. "The key long-term goal is to take any cell and de-differentiate it back into a stem cell," he added. "We could see this within 10 years."
Some of these new treatments may slow down the risk that someone might attempt human cloning, he said. "I have no doubt at all it is now possible to clone humans," he said. "There is no doubt that is where it is going to go."
It is not against US law to attempt human cloning but many countries have set ethical boundaries by making it illegal for, say, a doctor to become involved and still remain within the ethical limits set by the regulatory bodies.
"There is no medical justification for cloning," stated Prof David McConnell, professor of genetics at the Smurift Institute of Genetics at Trinity. It is misleading because a cloned human would be very unlike the original, he said.
He sees the exploration of the inner workings of the brain, consciousness and memory as one of the next great challenges in medical research. Use of the human genome will help and also having the chimpanzee genome, which gives a reference for comparison.
Prof McConnell believes we will be able to compare the proteins being expressed in the two species, which are so genetically close. This could give us insights into what genes come into play when we remember, think or feel.
Gene therapy is another key research area that will deliver important discoveries in the near future. There are dozens of inherited diseases caused when a person's DNA carries mutations, with the result being either missing or non-functional proteins.
With gene therapy, you install fully-functional replacement DNA that can deliver the missing proteins. "Any disease involving deficiencies of a protein will probably be cured by gene therapy," Prof O'Neill believes.
Gene replacement technology will probably be routine within 10 years and may also be an important part of cancer therapy, according to Prof Martin Clynes, professor of biotechnology and director of the National Institute for Cellular Biotechnology at Dublin City University.
Gene replacement also has its ethical difficulties, particularly in germ-line gene therapy, he said. Existing research is directed towards gene replacements that cannot subsequently be inherited. No change is being made to either sperm or egg cells.
Prof Clynes sees great potential for eliminating disease inheritance through permanent change to the germ cells. This could only arrive, he adds, in the context of "considerable control to prevent master-race type of germ-line genetic engineering and human cloning".
There are similar difficulties with research into zenotransplantation, using genetically engineered animals that express human proteins as a source of replacement organs, he added. "This could become a central part of medical practice but the efficacy, biological safety and side-effects issues are not yet entirely clear."
All of the researchers expect great changes in the development of new medicines. The human genome project has accelerated research into the proteins manufactured by the DNA code. Proteins, when formed, adopt very precise shapes that fit lock-and-key style into unique locations inside the cell, initiating or shutting down processes.
If you know the DNA, then you will know the protein and how it might function. If you know its function, you can use this to make new and better treatments.
This work hinges on the use of computers to scan the genome, identify genes and model the proteins they produce. "At the moment, 90 per cent of research is done as in vitro and in vivo science. I think that is going to completely reverse," Dr O'Farrelly said. There will be a new computer approach known as in silico testing, using computer models.
"We will be able to predict the size of proteins and the model will build their structures. Rational drug design will become a reality." Researchers will discover the biochemistry behind a disease and then produce a custom-designed drug that cures it.