FAP-positive CAFs drive tumorigenesis and metastasis through four key mechanisms: (i) promoting extracellular matrix (ECM) remodelling via its collagenolytic activity, (ii) stimulating angiogenesis to support tumour vasculature, (iii) establishing an immunosuppressive TME through cytokine secretion, and (iv) facilitating intracellular signalling pathways that enhance tumour cell survival [123]. The gene discussed is FAP; the disease is neoplasm.