Within the next month or two, the US Senate will vote on a bill that would ban research into therapeutic cloning — the creation of cloned human embryos to extract embryonic stem (ES) cells matched to individual patients. The result is too close to call, and lobbying for and against has reached fever pitch.

In this febrile atmosphere, unpublished scientific claims are assuming a weight usually afforded to peer-reviewed results (see Nature 415, 722; 2002). Last week, for instance, The Wall Street Journal discussed unpublished claims by Chinese researchers to have extracted ES cells from cloned embryos created by fusing human cells with rabbit eggs. Supporters of therapeutic cloning argued that other nations stand to reap the economic benefits if the United States turns its back on the field; opponents seized on the 'yuk' factor of combining human and animal material.

Even basic terminology is being reinvented. While the anti-abortion lobby characterizes therapeutic cloning as 'clone and kill' medicine, the presidents of the National Academy of Sciences and the Institute of Medicine argue that 'therapeutic cloning' should be abandoned in favour of the phrase 'somatic cell nuclear transfer' (Science 295, 1237; 2002). The latter phrase is conceptually accurate, and in avoiding the word 'cloning' makes a clear distinction between reproductive cloning and the therapeutic procedure. But it hardly trips off the layperson's tongue, and may create the impression that scientists want to hide the fact that the procedure involves creating an embryo — albeit one consisting merely of a hollow ball of cells.

This is the background against which President George W. Bush is expected to announce this week that Elias Zerhouni, executive vice-dean of the Johns Hopkins University School of Medicine in Baltimore, Maryland, is his nominee for the post of director of the National Institutes of Health (NIH). Zerhouni was reportedly selected ahead of Tony Fauci, the widely tipped director of the National Institute of Allergy and Infectious Diseases (NIAID), because he was willing to endorse Bush's support for a ban on therapeutic cloning. Fauci, it is alleged, was insufficiently 'pro-life' to be trusted with the top NIH post.

Wisely, Zerhouni is keeping his own counsel. But when the time for his confirmation hearings in the Senate comes round, it is to be hoped that his position on ES-cell research and cloning does not dominate the discussion to the exclusion of all else.

Once US federal policy on cloning has been decided, Zerhouni's personal position will be moot. But the other issues facing the NIH will remain. Departed senior staff will still need to be replaced; debates about priorities in genome research will still need to be resolved; and the new director must develop a fruitful working relationship with Fauci so that the vast injection of funds into the NIAID for research into countering bioterrorism is wisely spent.

The senators who will debate Zerhouni's appointment should put his position on cloning to one side, and concentrate on examining how his experience at Johns Hopkins qualifies him to deal with the rest of the NIH's agenda.