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 .
Autoimmune diseases occur when the body mistakes its own tissues for pathogens. The results of this self-destruction are very different, even when the body attacks the same system. Here, we'll compare and contrast Graves' disease and Hashimoto's thyroiditis, two autoimmune diseases of the thyroid.