CD21
E902889
CD21 is a complement receptor (CR2) found on B cells and follicular dendritic cells that plays a key role in B cell activation and the immune response.
All labels observed (2)
| Label | Occurrences |
|---|---|
| B cell coreceptor complex | 1 |
| CD21 canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T11074461 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: CD21 Context triple: [B lymphocytes, express, CD21]
-
A.
CD46
CD46 is a human cell-surface complement regulatory protein that also serves as an entry receptor for various pathogens, including certain adenoviruses and measles virus.
-
B.
CD38
CD38 is a cell surface glycoprotein with ectoenzyme and receptor functions, highly expressed on plasma cells and targeted in therapies for multiple myeloma and other hematologic malignancies.
-
C.
CD20 protein
CD20 protein is a cell-surface antigen found primarily on B lymphocytes and is a key therapeutic target in certain autoimmune diseases and B-cell malignancies.
-
D.
IL-64
IL-64 is a major east–west state highway in Illinois that runs from the Mississippi River through the Chicago metropolitan area.
-
E.
CD32
CD32 is a low-affinity Fc gamma receptor (FcγRII) found on various immune cells that plays a key role in modulating antibody-dependent immune responses.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: CD21 Target entity description: CD21 is a complement receptor (CR2) found on B cells and follicular dendritic cells that plays a key role in B cell activation and the immune response.
-
A.
CD46
CD46 is a human cell-surface complement regulatory protein that also serves as an entry receptor for various pathogens, including certain adenoviruses and measles virus.
-
B.
CD38
CD38 is a cell surface glycoprotein with ectoenzyme and receptor functions, highly expressed on plasma cells and targeted in therapies for multiple myeloma and other hematologic malignancies.
-
C.
CD20 protein
CD20 protein is a cell-surface antigen found primarily on B lymphocytes and is a key therapeutic target in certain autoimmune diseases and B-cell malignancies.
-
D.
IL-64
IL-64 is a major east–west state highway in Illinois that runs from the Mississippi River through the Chicago metropolitan area.
-
E.
CD32
CD32 is a low-affinity Fc gamma receptor (FcγRII) found on various immune cells that plays a key role in modulating antibody-dependent immune responses.
- F. None of above. chosen
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
cell surface receptor
ⓘ
complement receptor ⓘ immune system protein ⓘ membrane glycoprotein ⓘ |
| associatedWithDisease |
Epstein–Barr virus infection
ⓘ
chronic lymphocytic leukemia ⓘ common variable immunodeficiency (some forms) ⓘ systemic lupus erythematosus ⓘ |
| bindsMolecule |
C3d
ⓘ
C3dg ⓘ CD23 ⓘ Epstein–Barr virus gp350/220 ⓘ iC3b ⓘ |
| encodedByGene | CR2 gene ⓘ |
| expressedOnCellType |
B cells
ⓘ
follicular dendritic cells ⓘ some T cell subsets (low levels) ⓘ some epithelial cells ⓘ |
| formsComplexWith |
CD19
ⓘ
CD225 ⓘ CD81 ⓘ |
| hasDomain |
extracellular domain with multiple SCR (short consensus repeat) domains
ⓘ
short cytoplasmic tail ⓘ single transmembrane domain ⓘ |
| hasFunction |
enhances B cell receptor signaling
ⓘ
facilitates immune memory formation ⓘ lowers B cell activation threshold ⓘ mediates complement-dependent B cell activation ⓘ participates in germinal center reactions ⓘ retains antigen on follicular dendritic cells ⓘ |
| hasSynonym |
C3d receptor
ⓘ
CR2 ⓘ complement receptor type 2 ⓘ |
| locatedOnChromosome | human chromosome 1q32 ⓘ |
| memberOf |
CD2 family
ⓘ
complement system receptors ⓘ |
| orthologFoundIn |
mouse
ⓘ
other mammals ⓘ rat ⓘ |
| participatesInPathway |
adaptive immune response
ⓘ
complement activation-dependent B cell signaling ⓘ germinal center formation ⓘ |
| partOf |
B cell coreceptor complex
ⓘ
linked to:
CD21
|
| recognizedBy |
monoclonal antibody clone B-ly4
ⓘ
monoclonal antibody clone HB-5 ⓘ |
| subcellularLocation | plasma membrane ⓘ |
| topology | type I transmembrane protein ⓘ |
| usedAsMarkerFor |
follicular dendritic cells
ⓘ
mature B cells ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: CD21 Description of subject: CD21 is a complement receptor (CR2) found on B cells and follicular dendritic cells that plays a key role in B cell activation and the immune response.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.