Stem Cell Surprise: Blood cells form liver, nerve cells

A person’s blood could someday provide replacement cells for that individual’s damaged brain or liver, a provocative study suggests. Human blood contains so-called stem cells that can be transformed outside the body into a variety of cell types, according to the report. This unexpected, and accidental, discovery may add a new element to the politicized debate over whether stem cells that persist in adults can match the therapeutic potential of stem cells derived from human embryos.