THE EDUCATION LIBRARY
Immune-hot, excluded, or cold
This is the synthesis layer of reading a tumor: after morphology, genomics, transcriptomics, proteomics, and spatial profiling, the practical question is whether the immune system is already in the tumor, stuck at the edge, or mostly absent.
For Diana's active decision page, see is-tumor-hot. Keep this page in the education walkthrough so the Reading a Tumor section has a local child page for the concept.
The three states
| State | What it means | Why it matters |
|---|---|---|
| Immune-hot | T cells are present in the tumor and inflammatory signaling is active. | Checkpoint release has something to rescue. |
| Immune-excluded | T cells are nearby but held at the border by stroma, vasculature, or suppressive signaling. | The problem is trafficking or access, not only T-cell activation. |
| Immune-cold | Few tumor-reactive T cells are present. | Vaccines or priming strategies may matter more than releasing a brake. |
What reads it
- H&E and sTIL scoring show whether lymphocytes are visible in the tumor bed.
- RNA immune signatures show interferon signaling, cytotoxic activity, and subtype.
- Spatial or multiplex imaging distinguishes true infiltration from edge-only exclusion.
- ctDNA and early response readouts help decide whether the immune state is translating into treatment effect.
For the full ladder of immune readouts -- sTIL scores, T-cell infiltration, tissue and blood TCR-seq, single-cell RNA/TCR sequencing, and ctDNA pairing -- see measuring-t-cell-engagement.
Related
- reading-a-tumor — how diagnostic layers build toward this state call
- measuring-t-cell-engagement — how each immune-monitoring assay reads a different layer of T-cell engagement
- is-tumor-hot — Diana-specific decision page
- is-pembro-working — how tumor state informs pembrolizumab interpretation