As cells age, they eventually stop multiplying, a state known as 'senescence.' Accumulation of senescent cells is thought to contribute to the symptoms of aging. A study examining T cells, a type of immune cell, found that lung cancer patients had more senescent T cells, much like healthy patients during aging. T cells from both aged individuals and lung cancer patients had increased levels of senescence-promoting proteins and lower levels of proteins that promote continued cell multiplication. This 'artificial aging' of immune cells may weaken the immune system’s ability to attack the cancer. The study’s authors suggest that treatments to ward off senescence in immune cells may in the future help avoid the weakening of the immune system seen in cancer and other aging-related diseases.