On August 9, 2001, the President announced his decision to allow Federal funds to be used for research on existing human embryonic stem cell lines as long as prior to his announcement (1) the derivation process (which commences with the removal of the inner cell mass from the blastocyst) had already been initiated and (2) the embryo from which the stem cell line was derived no longer had the possibility of development as a human being. In addition, the President established the following criteria that must be met:

• The stem cells must have been derived from an embryo that was created for reproductive purposes
• The embryo was no longer needed for these purposes;
• Informed consent must have been obtained for the donation of the embryo;
• No financial inducements were provided for donation of the embryo

UCSF developed two stem cell lines that met the President's criteria (HSF-1 & HSF-6). Detailed information about these stem cell lines is provided on this site.