Various antigens

Antigen is a general term for any molecule (commonly protein or polysaccharide, sometimes nucleic acid or small molecule) that is recognized by the adaptive immune system, specifically by antibodies or T-cell receptors[9][3][5]. Antigens may originate from outside the body (exogenous antigens, such as pathogens, allergens, food proteins), inside the body (endogenous antigens, such as those from viruses, intracellular bacteria, or mutated self-proteins), or may be altered self molecules (autoantigens, as in autoimmune disease)[9][3][5]. Tumor antigens are a subset, present on cancer cells, which can trigger an immune response[9][3]. "Various antigens" is not a standardized target or molecular entity; it encompasses a vast, diverse range of structures and functions, and cannot be meaningfully mapped to a canonical target or therapeutic class[9][3][5].