Acts of faith

WASHINGTON - The legal battle over worldwide markets for stem cell selection technology, pitting CellPro Inc. against the licensees of Johns Hopkins' CD34+ technology, are taking place in the context of a profound scientific uncertainty: both the companies and leading researchers acknowledge that the overall efficacy of blood stem cell transplantation is unknown.

While there are logical hypotheses about how the competing stem cell selection devices could be beneficial, no one knows whether they extend patients' lives. And because of the expense, complexity and time required to provide an answer, and the rapid pace of innovation in oncology, the question never may be answered...