**6. Conclusion**

As ageing is inevitably a biological process associated with the deterioration of functional activities and resistance to hazards of individuals, researchers are always interested in investigating the relevant factors affecting the ageing process. The continued combination of functional studies and molecular analyses in different age groups, different organisms, and different tissue types will hopefully provide the details necessary to comprehend this evolutionarily conserved fundamental process and to facilitate the development of therapeutic interventions to counteract ageinduced complications or to explore the direction of anti-ageing or rejuvenation. Our chapter revealed the role of epigenetic modification in ageing. Changes in epigenetic status have been shown to associate with ageing in many organisms. We focused on the role played by various histone modifications especially on histone methylation to lifespan modulation. Much more attention was on the SET-domain containing genes, *set-18*; further, we have shown that this gene regulates lifespan through *daf-16*, which is implicated in various mechanisms underlying ageing and oxidative stress. We demonstrated that *set-18* as an H3K36 dimethyltransferase is expressed specifically in muscle. Hence, their exact role in ageing and its underlying mechanism has yet to be explored, thus providing more directions and strategies for the rejuvenation of ageing and the recovering of age-related diseases.
