1.   Until now, scientists believed that specialized cells could not be used to form a complete living thing.

2.   At the same time, these experts said, creating specialized cells from embryonic stem cells has proved an elusive task.

3.   Before being injected into a patient, these specialized cells could be immortalized by adding the telomerase gene in active form.

4.   A group of cells organizes into regions of specialized cells.

5.   But in order to grow large numbers of specialized cells, Okarma said Geron will need to use its second technology, the immortalizing enzyme known as telomerase.

6.   But scientists say those cells may not be as useful to scientific research as embryonic stem cells because they have a limited ability to transform into specialized cell types.

7.   But the stem cells would never become just one type of cell, developing instead into mixtures of specialized cell types.

8.   Dendritic cells trap antigens like the cancer-associated protein and deliver them to T cells, specialized cells in the immune system that can destroy designated cells.

9.   For example, one criterion might be that a certain percentage of volunteers in study develop certain types of antibodies or specialized immune cells.

10.   From these embryos, they harvested embryonic stem cells, and then, in the laboratory, guided their growth into many different types of specialized cells.