 Immunosinescence is a process of gradual decline in the function of the immune system with age. It is characterized by increased inflammation, decreased production of new immune cells, and impaired ability to fight off infections. Immunosinescence is associated with several age-related diseases such as cancer, cardiovascular disease, and Alzheimer's disease. The underlying causes of immunosinescence include thymus atrophy, reduced number of naive T-cells, and increased production of pro-inflammatory cytokines. These factors lead to a decrease in the ability of the immune system to respond to pathogens and mount an effective defense against them. Additionally, immunosinescence can also cause an increase in the risk of developing certain types of cancer due to the accumulation of mutations in the immune system. This article was authored by Xiaoxu Liu, Jimeng Liang, Yuqing Ren, and others.