Combining rejuvenation interventions in rodents: a milestone in biomedical gerontology whose time has come.

Rejuvenation was originally proposed as easier than slowing aging because it targets initially inert changes to tissue structure and composition, rather than trying to disentangle processes that both create aging damage and maintain life. While recent studies support this hypothesis, a true test requires a panel of rejuvenation interventions targeting multiple damage categories simultaneously. Considerations of cost, profitability, and academic significance have dampened enthusiasm for such work, but it is vital. Now is the time for the field to take this key step toward the medical control of aging.