ABSTRACT
The immune system is a complex multi-cellular network, which can quickly accommodate or combat novel pathogens. This network of activating and inhibitory cells and molecules result in a tight balance between immunity and autoimmunity. It is the ability of the immune system to distinguish self from non-self that results in effective clearance of pathogens and immunologic memory. The primary challenge facing the field of tumor immunology is that, unlike infections, all tumor cells contain self-antigens that vary from normal tissue, primarily by mutation or by expression level. Many of these self-antigens are critical for biologic processes, such as DNA replication, or are expressed at some level on normal tissues. Thus, effective tumor immunity carries the risk of clinically significant autoimmunity.
