Today the National Institutes of Health reapproved the WiCell Research Institute's H9 (WA09) human embryonic stem (ES) cell line, the most used and cited in scientific research, for ongoing use in federally funded research. Last July, when the NIH adopted its new approval guidelines for human ES cell lines, the Wisconsin lines were not grandfathered for federal funding eligibility. Instead, the same detailed application and documentation required for new lines were required for Bush-era lines.