CXCL12 and neoplasm: This overlap blurs the line between tumor cells and stromal fibroblasts, so marker-based definitions alone can misidentify malignant cells as “CAFs.” Therefore, studies in sarcomas should (i) use lineage/copy-number-aware methods to distinguish aneuploid tumor cells from diploid stromal fibroblasts and (ii) combine markers with functional readouts (matrix stiffening/LOX activity, chemokine gradients such as CXCL12 or CXCL16, and spatial CD8+ T cell access).