Armored Personal Carrier. I think the APC is located where you find the Warden Crossbow.
Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. In other words, the body actually attacks its own cells. An immune disorder is when the body cannot defend itself. [ Source: http://www.chacha ....n immune disorder is when the body cannot defend itself. [ Source: http://www.chacha.com/question/what-is-the-difference-between-immune-disorders-and-autoimmune-diseases ]. More Answers to  What is the difference between immune disorders and autoimmune diseases .
In an autoimmune disease, the immune system mistakes part of your body â like your joints or skin â as foreign. It releases proteins called autoantibodies that attack healthy cells. Some autoimmune diseases target only one organ. Type 1 diabetes damages the pancreas. Other diseases, like lupus, affect the whole body.