The most important function of immune system is to defend the body from different disease causing pathogens. Whenever there is pathology in human body, immune system is activated to protect the vital tissues from harm.
The circumstances of their disappearances are all fascinating, and some, sadly, have never been found. One of the more high-profile missing persons cases of 2012 isn't actually a missing persons case at all. Katherine Jackson was reported as missing in late-July of 2012, by her nephew, Trent Jackson.
Location: National Parks in America Each year, hundreds of people are reported missing in national parks and forests. Most are eventually found, but there's a smaller category of cases that are never solved, including a few close to home. Most of those who have disappeared are children ages 20 months to 12 years and the elderly ages 74 to 85.