Moreover, unlike the nearby gastric wall, where both interstitial cells intensely positive for either PDGFRA or CD117 were present (Figure 3C‐D), the intramural periphery of GIST was intensely positive for PDGFRA only, with slightly focal, weak CD117 staining (Figure 3F‐G). This evidence concerns the gene PDGFRA and gastrointestinal stromal tumor.