FN1 and Salla disease: IHC using anti-EDB-FN (G4) mAb revealed distinct staining patterns of EDB-FN expression in the tumors across treatment groups: control tumors showed heterogeneous, moderate EDB-FN staining (Figure 2E) non-responding tumors displayed relatively weak staining throughout (Figure 2F) and the SD tumors exhibited strong staining, particularly intense in the tumor periphery compared to the core (Figure 2G).