In the Uro-2 panel, which marker localizes to the nucleus?

In the Uro-2 panel, which marker localizes to the nucleus?

• A. p53
• B. CK20
• C. CD44
• D. Ki-67

Answer: (A)

In immunohistochemistry, where a protein resides inside the cell guides how you read the stain. Nuclear localization means the stain concentrates in the cell nucleus, as seen with transcription factors or proliferation markers. In the Uro-2 panel, p53 is a nuclear protein, so its staining is confined to the nuclei of cells. CK20 is a cytokeratin and stains in the cytoplasm; CD44 is a cell-surface receptor and stains on the cell membrane. Ki-67 is also a nuclear-marker, but the item here points to p53 as the nucleus-localizing marker in this panel. So p53 shows the expected nuclear staining pattern used in this context.

In immunohistochemistry, where a protein resides inside the cell guides how you read the stain. Nuclear localization means the stain concentrates in the cell nucleus, as seen with transcription factors or proliferation markers. In the Uro-2 panel, p53 is a nuclear protein, so its staining is confined to the nuclei of cells. CK20 is a cytokeratin and stains in the cytoplasm; CD44 is a cell-surface receptor and stains on the cell membrane. Ki-67 is also a nuclear-marker, but the item here points to p53 as the nucleus-localizing marker in this panel. So p53 shows the expected nuclear staining pattern used in this context.