The neoplasm showed features of high-grade GIST with mitotically active spindle and epithelioid cells involving the gastric and perigastric adipose tissue (Figure 4(a), 60x magnification), and IHC staining demonstrated strong diffuse staining for CD117 (Figure 4(b), 20x magnification). The gene discussed is KIT; the disease is gastrointestinal stromal tumor.