CD33 as a Radioligand Therapy Target
CD33, CD33 molecule, is a cell-surface protein. In Human Protein Atlas immunohistochemistry, CD33 staining is highest in lymphoma (33% of samples positive). Clinical status: Clinical-stage (up to phase 3, any modality), with 2 active clinical trials.
Is CD33 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: Low IHC staining in lymphoma, 33% 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.
CD33 expression in cancer
Protein expression of CD33 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 | 0.19 | Low | 33% |
Not detected by IHC in: skin cancer, colorectal cancer, head and neck cancer, ovarian cancer, breast cancer, melanoma, kidney cancer, thyroid cancer, bladder cancer, neuroendocrine tumors, cervical cancer, lung cancer, pancreatic cancer, prostate cancer, gastric cancer, testicular cancer, endometrial cancer, glioma, liver cancer.
Is CD33 internalized?
Nuclens has not yet extracted internalization evidence for CD33. Internalization matters for radioligands because an internalizing receptor traps the radionuclide inside the tumor cell. Run a full analysis to pull the latest literature.
CD33 clinical trials
Clinical-stage (up to phase 3, any modality). 2 active trials reference CD33 (ClinicalTrials.gov, accessed 2026-08-31).
CD33 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 CD33 in the Human Protein Atlas tissue atlas, and read how normal-tissue expression predicts radioligand dosimetry risk.
CD33 gene essentiality (DepMap)
CRISPR knockout effect across 1252 cancer cell lines: 0.06 (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) · CD19 · SSTR2 · STEAP2 · CD22
See all radioligand therapy targets in lymphoma.
See how CD33 ranks against 15,000 targets for your indication.
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.