4 
Monitoring Stem Cell Research 
first successfully accomplished with human egg and sperm in 
1969. A decade later, after IVF had entered clinical practice for 
the treatment of infertility, arguments continued regarding the 
fate and possible uses of the so-called “spare embryos," em- 
bryos produced in excess of reproductive needs and subse- 
quently frozen and stored in the assisted-reproduction clinics. 
Although research using these embryos has never been illegal 
in the United States (except in a few states), the federal gov- 
ernment has never funded it, and since 1995 Congress has en- 
acted annual legislation prohibiting the federal government 
from using taxpayer dollars to support any research in which 
human embryos are harmed or destroyed. 
Although the arguments about embryo research had been 
going on for twenty-five years, they took on new urgency in 
1998, when the current stem cell controversy began. It was 
precipitated by the separate publication, by two teams of 
American researchers, of methods for culturing cell lines de- 
rived, respectively, from: (1) cells taken from the inner cell 
mass of very early embryos, and (2) the gonadal ridges of 
aborted fetuses. (In this report, we shall generally refer to the 
cell lines derived from these sources as, respectively, embry- 
onic stem cells [or “ES cells”] and embryonic germ cells [or "EG 
cells”]). This work, conducted in university laboratories in col- 
laboration with and with financial support from Geron Corpo- 
ration, prompted great excitement and has already led to much 
interesting research, here and abroad. It has also sparked a 
moral and political debate about federal support for such re- 
search: Is it morally permissible to withhold support from re- 
search that holds such human promise? Is it morally permissi- 
ble to pursue or publicly support (even beneficial) research 
that depends on the exploitation and destruction of nascent 
human life? 
Persons interested in the debate should note at the outset 
that ES and EG cells are not themselves embryos; they are not 
whole organisms, nor can they be made (directly) to become 
whole organisms. Moreover, once a given line of ES or EG cells 
has been derived and grown in laboratory culture, no further 
embryos (or fetuses) need be used or destroyed in order to 
work with cells from that line. But it is not clear whether these 
lines can persist indefinitely, and only very few lines, repre- 
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