Research on the longevity gene Klotho has yielded varying findings, with one study suggesting its knockout perturbs brain microRNAs and tRNA fragments linked to aging and Alzheimer's disease. However, other studies have found that deleting or modifying Klotho in certain contexts may not affect certain cognitive or cellular processes, or may even enhance cognition in aged nonhuman primates. The role of Klotho in aging and cognitive function appears to be complex and dependent on specific factors.