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.
Search engine Bing aggregated millions of search queries to find out who the most searched person of 2013 was and, no drum roll necessary, Mrs. Carter totally takes the crown. Beyonce dethroned Kim Kardashian, who was the most searched person in 2012.