Chronic low-grade inflammation is involved in the pathogenesis of many disease conditions in humans and it is frequently quantified by measuring the blood concentration of C-reactive protein (CRP). Here we show that the CRP concentration in old people (nonagenarians) is, at least partially, genetically determined, and that the high producer genotype is associated with a shorter life expectancy during follow-up. Thus, the data imply that the CRP gene may be a longevity gene in humans.