Werner et al. have studied the feasibility of CXCR4-PET in 12 GEP-NET, including five NET G-3, using 68Ga-Pentifaxor in comparison with 68Ga-DOTATOC PET-CT and 18F-FDG PET-CT: 80% of NET G-3 exhibited positive CXCR4-PET uptake (68Ga-Pentifaxor positive lesions) and increasing receptor expression was observed with increasing tumor grade [49]. The gene discussed is CXCR4; the disease is neoplasm.