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.
Missing people redirects here. For the UK charity, see Missing People. A missing person is a person who has disappeared and whose status as alive or dead cannot be confirmed as his or her location and fate are not known. person may go missing due to accident, crime, death in a location where they cannot be found (such as at sea), or many other reasons, including voluntary disappearance.