Preliminary work suggests that T-cells, which normally target disease, can be genetically engineered to target senescent cells in a wide range of tissues. In future, an infusion of GM blood every few years might be able to keep you going indefinitely (assuming some major advances in treating cancer, Alzheimer’s and heart disease). At which point, the question might be less: “How long have I got?” and more: “How long do you fancy sticking around?”

American scientists have coined the term ‘senolytics’ to describe a new class of drugs designed to delay the ageing process by clearing out doddery cells.