In a letter to the White House, 206 House members called for the President to expand his policy on embryonic stem cell research. The current policy limits the number of stem cell lines available for research with federal funds to the 78 lines derived before Aug. 9, 2001. Of those, the letter says, only 19 are currently usable--all of which are contaminated by mouse feeder cells. Funding concerns for this research are also making it difficult to attract scientists into the field and are pushing the field overseas, where embryonic stem cell research is not limited, the letter notes. "The merits and failures of stem cell research should be decided in the laboratories, not in the Oval Office," said Rep. Diana L. DeGette (D-Colo.), one of the leaders of the effort. The White House reportedly maintains that its current policy is adequate.