Via ScienceDaily: "We wanted to uncover the workings of skin health in order to see why older people don't deal well with skin infections and are prone to skin cancers also. ... In the past, the reduction in skin health was put down to potential defects in the white blood cells called T-cells that would usually help to identify and clear infection. However, when experiments were carried out with healthy young individuals under the age of 40 years and older individuals over the age of 70 years in this study, it was shown that in fact there is nothing wrong with the T-cells in the older group; instead it is the inability of their skin tissue to attract T-cells where and when they are needed that is the source of reduced immunity. ... Knowing this now raises the question of whether the same defect also occurs in other tissues during ageing. Is it possible that, for example, lung tissues also fail to give out the right message to T-cells to bring them into the tissue to do their job? This may explain, in part, the higher rates of lung cancer, chest infections and pneumonia in older people, perhaps. ... at least in the test tube, it is possible to make older skin express the missing signals that attract T cells. This indicates that, in principle, the defect is entirely reversible."