In the last few years, companies have started pursuing agonism of SIRT1 as a way of boosting the body's metabolism to treat Type II diabetes, while other researchers say they have evidence that activating the target might be useful in treating or preventing cancer.

But another camp is arguing that blocking, not activating, SIRT1 or other sirtuins could be used to treat cancer through the upregulation of tumor suppressor proteins. Pharmion Corp. is exploring that mechanism via last week's expanded deal with MethylGene Inc. Their 2006 deal will now include a project on selective inhibitors of SIRT1 and one or two of the six other members of the enzyme family.