Immunohistochemistry of SCGF expression in GIST samples. A) Hematoxylin-eosin section of one representative slide from GIST 5. B) SCGF staining; strong SCGF positivity, consistent with western blotting, was restricted to the stroma compartment. C) CD117 staining; cells retained weak cytoplasmic KIT reactivity. The rare viable tumoral cells present in the responding area were SCGF-negative in the cytoplasm and the nucleus. D) Hematoxylin-eosin section of one representative slide from GIST 2. Highly cellulated areas indicating the absence of pathological response are visible. Only two areas showing rare tumoral cells are present. E) CD117 staining; all cellulated areas exhibit strong KIT expression not observed in the acellulated areas mostly composed of stroma. F) SCGF staining; strong SCGF expression is restricted to the non-cellulated areas, in contrast to CD117 staining.