In immunology, cryptic self epitopes are a source of autoimmunity. In immunology, cryptic self epitopes are a source of autoimmunity. Self epitopes, which are found in high concentration on the surface of antigen-presenting cells (APC's) in association with its major histocompatibility complex (MHC) are known as dominant epitopes. These are stimulants of negative selection mechanisms to remove potentially self destructing autoreactive T cells. Their 'self' antigens are displayed to a developing T-cell and signal those 'self-reactive' T-cells to die via programmed cell death (apoptosis) and thereby deletion from the T cell repertoire, preventing autoimmunity.