The following discussion is purely theoretical and does not mean that it is feasible in practice or permitted by ethics and law. At present, the scientific community has not proved that "immortality" or "completely anti-aging" can be achieved through genetic engineering. Aging is an extremely complex biological phenomenon involving multiple intertwined processes inside and outside the cell. The following content is only used to introduce some current research directions and theoretical ideas in the field of aging biology. It does not constitute practical operation suggestions, nor does it encourage extremely risky experiments or genetic modification on the human body. [I. Main biological mechanisms of aging] 1. Telomere shortening: During cell division, the telomeres at the ends of chromosomes gradually shorten, and after reaching a certain extent, the cells lose the ability to divide. 2. Decreased DNA damage and repair ability: Long-term accumulated DNA damage and genomic instability may lead to decreased cell function. 3. Cell senescence and apoptosis: Cell senescence not only leads to cell dysfunction, but also may secrete inflammatory factors and affect the surrounding environment. 4. Mitochondrial function decline and oxidative stress: The energy produced by mitochondria gradually decreases, and more free radicals are produced to damage cells. 5. Epigenetic changes: Epigenetic changes such as DNA methylation and histone modification are closely related to cell aging. 【II. Theoretical strategies that genetic engineering may involve】 1. Extending telomere protection: a. Increasing the activity of telomerase (such as TERT gene) can theoretically delay telomere shortening and extend cell lifespan, but this will bring the risk of cancer, because overactive telomerase may cause cells to proliferate indefinitely. b. Regulating telomere binding proteins to improve telomere maintenance mechanisms. 2. Enhancing DNA repair mechanisms: a. Enhance the functions of genes related to DNA repair and genome stability (such as p53, BRCA1/2, etc.) through gene editing technology. b. Promote cell resistance to oxidative stress to reduce damage to DNA and organelles. 3. Regulating signal pathways of cell aging: a. Modify the functions of insulin/IGF-1 signaling pathways (such as FOXO gene group), and studies have shown that these pathways are related to lifespan. b. Use gene editing to regulate signal pathways closely related to metabolism and cell growth regulation, such as mTOR and AMPK. 4. Reprogramming and stem cell technology: Induce totipotent or pluripotent stem cells through genetic engineering to "reverse" some differentiated cells to a younger state. Research in this field (such as induced pluripotent stem cells, iPS technology) provides a strategy that may delay local tissue aging. 5. Elimination of senescent cells (Senolytics) related gene regulation: a. Through genetic modification, senescent cells in the body can be more easily eliminated, or the level of their secretion of pro-inflammatory substances (SASP, Senescence-Associated Secretory Phenotype) can be reduced. b. In theory, this may delay the aging process of the entire tissue, but it is currently mostly applied locally and its safety has not yet been determined. [III. Challenges and ethical issues] 1. Multi-factor and network complexity: Aging is not determined by a single gene, but the result of the synergistic action of hundreds of genes and molecular processes. Modification of a single or a few genes is likely to cause other side effects. 2. Cancer risk: Many strategies to extend cell life (such as activating telomerase) may also cause uncontrolled cell proliferation and lead to tumorigenesis. 3. Genetic background and individual differences: There are huge differences in the effects of genetic engineering in different individuals, otherwise it may cause unpredictable health problems. 4. Ethical and social controversy: Genetic modification of humans, especially those involving changes that affect basic biological characteristics (such as aging), has caused ethical, legal and social discussions around the world. 5. Difficulty in achieving "immortality": Even if some biological cells show the potential to extend lifespan, it is still an extremely large and complex project to coordinate various functions at the level of the entire organism and maintain the long-term stable operation of tissues and organs. [IV. Summary] Using genetic engineering technology to design a human who never ages is currently only in the stage of science fiction and theoretical discussion. At this stage, scientific research has not yet made breakthroughs in many key technologies, nor has it effectively solved the problem of side effects (such as tumor risks) that may be caused by delaying aging. In addition, any experiment involving human genome manipulation must undergo strict ethical review and long-term safety assessment. Therefore, although scientists have made some progress in delaying aging and improving healthy lifespan (such as using gene regulation, stem cell therapy, drug intervention, etc.), designing a completely ageless human is still far from becoming a reality. There may be more research and technology on how to delay aging in the future, but it is not right and impossible to "design" an individual who will not age through genetic engineering. Please note: The above content is limited to academic and theoretical discussions and shall not be used for any illegal or unethical practical activities. Any work involving human genetic modification or medical experiments must strictly comply with relevant laws and regulations and be approved by professional institutions.