Peter de Keizer

At a glance

• Peter de Keizer is a Dutch ageing biologist at UMC Utrecht. He studies senescent cells: damaged cells that stop dividing but do not die.
• These ‘zombie cells’ accumulate with age and secrete substances that promote inflammation and tissue damage.
• In a much-discussed study in Cell (2017), his team developed the peptide FOXO4-DRI. It disrupts the binding between the proteins FOXO4 and p53, causing senescent cells to die selectively.
• In fast-ageing and naturally old mice, fitness, fur and kidney function improved, among other things.
• He founded the company Cleara Biotech to develop this approach further, including for cancer treatment.
• For longevity, his work brought senolytics, drugs that clear senescent cells, a step closer to possible applications.
• Takeaway: FOXO4-DRI is not approved for human use; do not buy ‘senolytic’ peptides online.