12933 IUPAC Gold Book - B7 molecule 10.1351/goldbook.12933 12933 current 1 Co-stimulatory molecule on the surface of T-cell-activating antigen-presenting cells (APCs), allowing full activation of T cells that are bound to major histocompatibility complex (MHC)-peptide complexes. Whereas binding of B7 molecules to CD28 is stimulatory, binding to cytotoxic T-lymphocyte antigen-4 (CTLA-4) decreases T-cell activity and participates in tolerance. Co-stimulatory molecule https://goldbook.iupac.org/terms/view/13051 T-cell https://goldbook.iupac.org/terms/view/13724 activation https://goldbook.iupac.org/terms/view/13401 antigen-presenting cells (APCs) https://goldbook.iupac.org/terms/view/12888 cytotoxic T-lymphocyte antigen-4 (CTLA-4) https://goldbook.iupac.org/terms/view/13073 major histocompatibility complex (MHC) https://goldbook.iupac.org/terms/view/13430 tolerance https://goldbook.iupac.org/terms/view/13302 PAC, 2012, 84, 1113. 'IUPAC glossary of terms used in immunotoxicology (IUPAC Recommendations 2012)' on page 1132 (https://doi.org/10.1351/PAC-REC-11-06-03) https://goldbook.iupac.org/terms/view/12933/html https://goldbook.iupac.org/terms/view/12933/json https://goldbook.iupac.org/terms/view/12933/plain Citation: 'B7 molecule' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.12933 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-05-14T13:48:08+00:00