What are antigens?

Some articles on antigens, antigen:

Classification of Tumor Antigens
... on their pattern of expression Tumor-Specific Antigens (TSA), which are present only on tumor cells and not on any other cell and Tumor-Associated Antigens (TAA), which are present on some ... classification, however,is imperfect because many antigens thought to be tumor-specific turned out to be expressed on some normal cells as well ... The modern classification of tumor antigens is based on their molecular structure and source ...
History And Naming Of Human Leukocyte Antigens - Genetic Complexity Typifies HLA - Serotype Group Expansion and Refinement
... By the mid 1970s, genetic research was finally beginning to make sense of the simple list of antigens, a new series "C" had been discovered and, in turn genetic research had ... With new series came new antigens Cw1 and 2 were quickly populated, although Cw typing lagged ... Almost half of the antigens could not be resolved by serotyping in the early 90s ...
Sensitization (immunology)
... To bind antibodies or soluble antigens chemically or by adsorption to appropriate biological entities such as erythrocytes or particles made of gelatin or latex for passive aggregation tests ... themselves are biologically inactive except for serving as antigens against the primary antibodies or as carriers of the antigens ...
History And Naming Of Human Leukocyte Antigens
... Human leukocyte antigens (HLA) began as a list of antigens identified as a result of transplant rejection ... The antigens were identified based on serotypes that developed in transplant recipients, to donor antigens that could recognize one apparent antigen were found ... HLA are not typical antigens, like those found on surface of infectious agents ...
CD4+ T Cells And Antitumor Immunity - Tumour Antigens
... Tumour antigens are those expressed by tumor cells, and recognizable as being different from self cells ... Most currently classified tumor antigens are endogenously synthesized, and as such are presented on MHC class I molecules to CD8+ T cells ... Such antigens include products of oncogenes or tumor suppressor genes, mutants of other cellular genes, products of genes that are normally silenced, over-expressed gene ...