Fig. 1

The process of immunosenescence. The process of immunosenescence can alter the immune response, thus leading to the occurrence of various diseases, such as tumors and infections. Many factors can activate the immunosenescence process: the thymus gradually degenerates, resulting in an age-related decrease in T cell output and leading to the senescence of the immune system; inflammation related to advanced age will produce SASP, which also leads to immunosenescence; the intrinsic factors in immune system cells as well as potential extrinsic factors that are often overlooked, can also cause immunosenescence