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 .
An autoimmune disease is a disease where the body attacks itself by means of antibodies. One consequence of the body attacking itself is inflammation in areas of the body that aren't injured or damaged.