Microsoft Word Kurzweil, Ray The Singularity Is Near doc

Human Somatic-Cell Engineering.
This even more promising approach, which bypasses the controversy of using 
fetal stem cells entirely, is called transdifferentiation; it creates new tissues with a patient's own DNA by converting 
one type of cell (such as a skin cell) into another (such as a pancreatic islet cell or a heart cell).
62
Scientists from the 
United States and Norway have recently been successful in reprogramming liver cells into becoming pancreas cells. In 
another series of experiments, human skin cells were transformed to take on many of the characteristics of immune-
system cells and nerve cells.
63
Consider the question, What is the difference between a skin cell and any other type of cell in the body? After all, 
they all have the same DNA. As noted above, the differences are found in protein signaling factors, which include 
short RNA fragments and peptides, which we are now beginning to understand.
64
By manipulating these proteins, we 
can influence gene expression and trick one type of cell into becoming another. 
Perfecting this technology would not only defuse a sensitive ethical and political issue but also offer an ideal 
solution from a scientific perspective. If you need pancreatic islet cells or kidney tissues—or even a whole new 
heart—to avoid autoimmune reactions, you would strongly prefer to obtain these with your own DNA rather than the 
DNA from someone else's germ-line cells. In addition, this approach uses plentiful skin cells (of the patient) rather 
than rare and precious stem cells. 
Transdifferentiation will directly grow an organ with your genetic makeup. Perhaps most important, the new 
organ can have its telomeres fully extended to their original youthful length, so that the new organ is effectively young 
again.
65
We can also correct accumulated DNA errors by selecting the appropriate skin cells (that is, ones without 
DNA errors) prior to transdifferentiation into other types of cells. Using this method an eighty-year-old man could 
have his heart replaced with the same heart he had when he was, say, twenty-five. 
Current treatments for type 1 diabetes require strong antirejection drugs that can have dangerous side effects.
66
With somatic-cell engineering, type 1 diabetics will be able to make pancreatic islet cells from their own cells, either 
from skin cells (transdifferentiation) or from adult stem cells. They would be using their own DNA, and drawing upon 
a relatively inexhaustible supply of cells, so no antirejection drugs would be required. (But to fully cure type 1 
diabetes, we would also have to overcome the patient's autoimmune disorder, which causes his body to destroy islet 
cells.) 
Even more exciting is the prospect of replacing one's organs and tissues with their "young" replacements without 
surgery. Introducing cloned, telomere-extended, DNA-corrected cells into an organ will allow them to integrate 
themselves with the older cells. By repeated treatments of this kind over a period of time, the organ will end up being 
dominated by the younger cells. We normally replace our own cells on a regular basis anyway, so why not do so with 
youthful rejuvenated cells rather than telomere-shortened error-filled ones? There's no reason why we couldn't repeat 
this process for every organ and tissue in our body, enabling us to grow progressively younger.