Hwang and his colleagues states that they exchanged the nucleus of unfertilized egg of a human for the nucleus of an ordinary cell, taken from another human, and created the lines made of stem cells from an embryo that appeared as the result. These stem cells coincidedwith the DNA of the man who provided an ordinary cell. This experiment demonstrated that it is now possible to give a cell or a tissue to a person, and they will not be rejected by the organism, having been cloned from them. (Singer)
The experiments of Hwang haven't been completed. However, he assumed that definite problems might occur. He insisted on the legitimacy of his work, confessing that there may be errors in the lines of stem cells. He also confessed that few cells could be damaged. At any rate, the scientists consider this be one of the most significant discoveries in medicine and biology. Of course, experiments and researches are needed, but the results will significantly change the whole medical practice. (Robertson)
But ethical background of this invention is discussed by many scientists. It shows that the potential of human life is included into each cell of our organism, and this would change the discussion about the value of a human life.