Mr. Greenwood expressed doubt that 60 or more embryonic stem cell lines existed.

Making embryonic stem lines from cancer patients could help identify and focus on cancer stem cells.

With the parents' consent these cells could also be used for research, providing many new embryonic stem cell lines for laboratories.

To avoid legal issues with working with pure human embryonic stem cell lines.

"Some embryonic stem cell lines make particular tissues better than others."

Expanding research to more embryonic stem cell lines.

"And so, therefore, I'm against the extension of the research, of using more federal dollars on new embryonic stem cell lines."

He made a Solomonic choice, permitting federal financing for research on a limited number of embryonic stem cell lines, but only those that already existed.

He voted against expanding research to more embryonic stem cell lines.

Second, we can encourage research on embryonic stem cell lines that already exist.