Francis Collins, the director of the National Institutes of Health, approved eight more human embryonic stem cell lines for federal funding earlier this week. His decision brings to 75 those lines now available to NIH-supported researchers under President Barack Obama’s liberalized, 2009 policy.

But Collins formally rejected 47 lines – 42 of which are disease-specific – following the recommendations of a group of external advisors reported in last week in Nature (see: Diseased cells fail to win approval).

Collins said in a statement that he agreed with his advisors that the consent form signed by couples who donated the embryos from which the lines were derived “was inconsistent with the basic ethical principle of voluntary consent”. The form, used by the Reproductive Genetics Institute in Chicago, Illinois, asked couples to broadly waive their rights to sue the institute for reasons related to their donation.

All the lines so far approved, along with lines that have been submitted to the agency but not yet ruled on, can be viewed at the NIH stem cell registry. The registry also lists those lines in “draft status,” whose owners have begun applying to the agency for approval but not yet completed their applications.