MUM1/IRF4 IHC (Multiple Myeloma oncogene 1)
Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.
| ID | BIO-MUM1-IHC |
|---|---|
| Type | Biomarker |
| Aliases | IRF4 IHCInterferon Regulatory Factor 4MUM1 immunohistochemistryMUM1/IRF4 protein expression |
| Status | reviewed 2026-05-05 | pending_clinical_signoff |
| Diseases | None declared |
| Sources | SRC-NCCN-B-CELL-2025 |
Biomarker Facts
| Biomarker type | protein_expression_ihc |
|---|---|
| Mutation details | {"gene_id_ncbi": 3662, "gene_symbol": "IRF4", "note": "IRF4/MUM1 is a transcription factor expressed in post-germinal center B-cells, plasma cells, T-cells (activated), and NK-cells. In DLBCL: MUM1 positivity (>30% of tumor cells) in the Hans algorithm Step 3 context indicates non-GCB/ABC subtype. Nuclear staining pattern.\n"} |
| Measurement | MethodIHC on FFPE biopsy. Anti-MUM1/IRF4 antibody (clone MUM1p). Nuclear staining. Cut-off: >30% positive tumor cell nuclei = MUM1 positive. Hans algorithm Step 3: when CD10 negative AND BCL6 positive — MUM1 determines final COO: MUM1 >30% → non-GCB; MUM1 ≤30% → GCB. |
| Related biomarkers | BIO-CD10-IHC BIO-BCL6-IHC BIO-DLBCL-COO-HANS BIO-CD30-IHC |
Notes
MUM1/IRF4 IHC completes the Hans algorithm for DLBCL COO classification. The Hans algorithm has ~80% concordance with GEP (Lymph2Cx) for GCB/non-GCB classification. Non-GCB DLBCL (by Hans) has historically worse prognosis with R-CHOP and is the target of emerging combination therapies (e.g., lenalidomide + R-CHOP = R²-CHOP in the Phoenix trial — showed benefit in young/fit non-GCB, particularly non-GCB by COO). The Hans IHC panel (CD10, BCL6, MUM1) is recommended in all DLBCL where molecular COO profiling is not available.
Used By
Biomarker
BIO-BCL6-IHC- BCL6 IHC (protein expression)BIO-CD10-IHC- CD10 IHC (CALLA, neprilysin)