Figure 1. Living better for longer.

a, Nucleotide excision repair (NER) is a process by which DNA damage is repaired. Mice that harbour genetic mutations in the genes Ercc1 or Xpg are NER deficient. DNA damage accumulates, signalling through the protein IGF1 is suppressed, and mice age at an accelerated rate. The pathways by which these processes influence ageing are unclear (dashed arrows). b, Vermeij et al.¹ report that restricting the diets of NER-deficient mice reduces DNA damage and further suppresses IGF signalling. The average lifespan of the mice significantly increases compared with counterparts that eat freely, and they remain healthy for much longer.