CD19 as a Radioligand Therapy Target
CD19, CD19 molecule, is a cell-surface protein. In Human Protein Atlas immunohistochemistry, CD19 staining is highest in lymphoma (73% of samples positive), neuroendocrine tumors (25% of samples positive) and prostate cancer (9% of samples positive). Clinical status: Clinical-stage (up to phase 3, any modality), with 3 active clinical trials.
Is CD19 a good radioligand therapy target?
Scored against the six criteria that decide whether a protein can become a radioligand therapy:
- ✅ Cell-surface accessibility: Localized to the cell surface, so a radioligand can reach it from circulation.
- ✅ Tumor expression: High IHC staining in lymphoma, 73% of samples positive.
- ❔ Internalization: Not yet assessed.
- ✅ Clinical precedent: Clinical-stage (up to phase 3, any modality)
- ❔ Shedding: Not yet assessed.
- ❔ Normal-tissue dosimetry: Check kidney, liver, bone marrow and salivary expression in the Human Protein Atlas tissue atlas.
CD19 expression in cancer
Protein expression of CD19 across 20 cancer types from Human Protein Atlas immunohistochemistry. The score is a weighted staining intensity from 0 to 1; "% positive" is the share of patient samples with detectable staining.
| Cancer type | IHC score | Level | % positive |
|---|---|---|---|
| Lymphoma | 0.64 | High | 73% |
| Neuroendocrine Tumors | 0.08 | Low | 25% |
| Prostate Cancer | 0.06 | Low | 9% |
| Melanoma | 0.06 | Low | 8% |
| Pancreatic Cancer | 0.03 | Low | 10% |
| Liver Cancer | 0.03 | Low | 10% |
Not detected by IHC in: skin cancer, colorectal cancer, head and neck cancer, ovarian cancer, breast cancer, kidney cancer, thyroid cancer, bladder cancer, cervical cancer, lung cancer, gastric cancer, testicular cancer, endometrial cancer, glioma.
Is CD19 internalized?
Nuclens has not yet extracted internalization evidence for CD19. Internalization matters for radioligands because an internalizing receptor traps the radionuclide inside the tumor cell. Run a full analysis to pull the latest literature.
CD19 clinical trials
Clinical-stage (up to phase 3, any modality). 3 active trials reference CD19 (ClinicalTrials.gov, accessed 2026-09-28).
NCT07162038 · NCT04732845 · NCT07838714
CD19 normal tissue expression
Normal-tissue expression in dose-limiting organs (kidney, liver, bone marrow, salivary glands) drives radioligand dosimetry risk. Nuclens is re-validating its normal-tissue values, so they are not shown here yet. See CD19 in the Human Protein Atlas tissue atlas, and read how normal-tissue expression predicts radioligand dosimetry risk.
CD19 gene essentiality (DepMap)
CRISPR knockout effect across 1241 cancer cell lines: -0.08 (not essential). Radioligands kill by radiation, not by blocking the target, so essentiality matters less than for inhibitors. A non-essential target can still be an excellent radioligand target.
Related lymphoma radioligand targets
c-MET (MET) · CD20 (MS4A1) · HER3 (ERBB3) · CD45 (PTPRC) · SSTR2 · STEAP2 · CD22 · TMEFF2
See all radioligand therapy targets in lymphoma.
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Run a free analysisData sources
Subcellular localization: UniProt via Open Targets (CC BY 4.0 / CC0). Tumor immunohistochemistry: Human Protein Atlas (CC BY-SA 4.0). Clinical trials: ClinicalTrials.gov (public domain). Gene essentiality: DepMap (CC BY 4.0). Internalization and shedding: AI-extracted from PubMed abstracts, so verify against the cited papers before relying on them. Nuclens is a first-pass triage layer, not a substitute for wet-lab validation or clinical dosimetry. Derived expression data on this page is shared under CC BY-SA 4.0.