Telling someone to “act your age” is another way of asking him or her to behave better. Age, however, does not always bring improvements. Certain cells of the immune system tend to misbehave with age, leaving the elderly more vulnerable to illness. Because these cells are known to misbehave similarly during spaceflight, researchers are studying the effects of microgravity on immune cells to better understand how our immune systems change as we age.
from Space & Time News — ScienceDaily http://ift.tt/1mvut3z