TGF-β
A growth factor that starts as a brake and becomes an accelerator: late in cancer it drives invasion, activates fibroblasts, and walls T cells out of the tumour.
Diagram
Pick a product above a diagram to see the nodes it hits and the escape routes below the block. Hover or tap any node or arrow for what it is; every node opens its target, glossary entry or the pathway page. Violet boxes are druggable targets.
A town planner who first refuses all new building (tumour suppressor) and then, corrupted, builds walls and moats around the tumour that keep the police out (immune exclusion).
What happens
In plain words, then the glossary entries the stage rests on. Chapter 6, Escaping the immune system: Every tumour that exists has already beaten the immune system once.
A growth factor that starts as a brake and becomes an accelerator: late in cancer it drives invasion, activates fibroblasts, and walls T cells out of the tumour.
TGF-β signalling. A signal that stops normal cells from dividing but, once a cancer is established, switches sides: it builds scar-like stroma, walls out immune cells, and pushes cells into a migratory state.
The molecular players
The proteins and genes at this stage, with their role and how many products act on each. Listed players come from the atlas; drawn players sit as nodes in the diagrams above.
FAP (fibroblast activation protein) sits on the cancer-associated fibroblasts that scaffold more than 90% of epithelial cancers and is almost absent from normal adult tissue. FAPI PET tracers therefore light up tumours with high contrast, including pancreatic, gastric and low-grade cancers where FDG PET is weak, and FAP-targeted radioligands are in development.
Where medicines act
Products grouped by the node they hit, most advanced first, with the cancers an approved product is linked to. Pick one above the diagram to see it light up.
- EB-MF-CAR-NK-01Phase 2
- FAP-2286 (177Lu / 68Ga)Phase 2
How tumours escape
Records tied to this stage that describe resistance, evasion or tolerance. The resistance atlas lists the routes class by class.
Open questions
What is not known at this stage: the atlas's own questions, the bottlenecks it bears on, and the ideas in the corpus that try to answer them.
- Is TGF-β blockade salvageable with the right selectivity (TGF-β1 only) or local delivery?
- Which patients have TGF-β-driven exclusion versus other causes?
- early clinicalindustryClear the suppressive neutrophils out of pancreatic tumours first
Pancreatic tumours are packed with a type of white blood cell that shuts down the immune attack. Blocking the signal that recruits them may open the tumour to immunotherapy.
- early clinicalFAP theranostics as a pan-cancer stromal strategy
Instead of finding a different target for each cancer, hit the scaffolding cells that almost all solid tumours share.
- early clinicalWhat actually holds T cells at the tumour border?
In immune-excluded tumours T cells reach the border but cannot get in, held back by fibroblasts, matrix, abnormal vessels, CXCL12 gradients or myeloid cells, and TGF-β drugs on their own have failed. If single-cell and spatial profiling can show which stromal programme dominates in each tumour, matching the drug (TGF-β, FAP, CXCR4 or VEGF) to it could let immunotherapy work.
- preclinical evidenceindustryAnchor a TGF-beta trap in the tumour stroma so it cannot act everywhere
TGF-beta is a signal that keeps immune cells out of tumours, but blocking it throughout the body caused bleeding and heart toxicity and sank bintrafusp alfa. Tethering the blocker to tumour stroma with a FAP anchor, a collagen-binding domain or a protease-activated mask could give the benefit without the harm.
- preclinical evidenceresearchBlock the survival signals the tumour's neighbours provide
Cancer cells can survive a drug because surrounding normal cells feed them growth signals. Blocking those signals could make existing drugs work better and longer.
- preclinical evidenceresearchMake every cold tumour hot: a coordinated programme to reprogramme immune-excluded tumours
Immunotherapy works in tumours that immune cells can enter and ignores those that shut them out. Systematically test ways to open up the shut-out tumours, measured with spatial maps.
- preclinical evidenceresearchSoften the tissue that new metastases need in order to grow
Cancer cells need stiff, cross-linked tissue scaffolding to settle and grow in a new organ. Blocking the enzymes that build it may stop new colonies taking hold.
- speculativeFAPI PET as the workup for MCED positives
When a blood test says 'cancer signal, origin unclear', a FAPI PET scan may find it where FDG cannot.
- speculativeresearchMatch therapy to the type of scar-forming cell in the tumour
The support cells that build a tumour's scaffolding come in several types: some protect the tumour, others restrain it. Treating all of them the same way explains past failures.
Key evidence
Papers in the corpus tied to this stage's pathways, targets and terms, newest first.
- 2023rctCOMMANDS: luspatercept versus epoetin alfa as first treatment for anaemia in lower-risk MDS needing transfusionsThe Lancetchanged practice
- 2018observationalTGFβ attenuates tumour response to PD-L1 blockade by contributing to exclusion of T cellsNature
- 2018basicTGFβ drives immune evasion in genetically reconstituted colon cancer metastasisNature
- 2014reviewLamouille 2014: molecular mechanisms of epithelial-mesenchymal transitionNature Reviews Molecular Cell Biology
- 2009reviewKalluri and Weinberg 2009: the basics of epithelial-mesenchymal transitionJournal of Clinical Investigation
- 2008basicMani 2008: the epithelial-mesenchymal transition generates cells with properties of stem cellsCell
src/data/mechanics-atlas.ts). Players, medicines, escape routes, tests, ideas and papers are resolved from the knowledge graph at build time through the stage's pathways, targets and terms, so every item here has its own page and sources. Where a section is missing, the corpus has no record tied to the stage yet. Nothing here is medical advice; see about and methodology. Stage 6.5 of 56.