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 disease can be either organ-specific illnesses (eg, thyroid disease, type 1 diabetes mellitus, myasthenia gravis) or systemic illnesses (eg, rheumatoid arthritis (RA), systemic lupus erythematosus (SLE)). The cause of autoimmune damage may be mainly due to either autoantibodies or autoimmune T lymphocytes.