DPP4 is expressed on numerous tumors, including malignant pleural mesothelioma (MPM), renal cell carcinoma (RCC), gastrointestinal stromal tumor (GIST), hepatocellular carcinoma (HCC), and colorectal, lung, prostate, and ovarian cancer [2]. The gene discussed is DPP4; the disease is gastrointestinal stromal tumor.