In contrast, in the periphery, Shi et al. reported 68Ga-labeled COG1410, an ApoE-derived peptide that targets TREM2 on tumor-associated macrophages (TAMs) for the diagnosis of gastrointestinal tumors 34, and 124I- and 99mTc-labeled antibody fragments showing potential for targeting human TREM2 in gastric carcinoma 35 and lung cancer 36. The gene discussed is TREM2; the disease is digestive system neoplasm.