We identified 22 lncRNAs (DOCK9-DT, AC046143.1, AC022509.2, MIR181A2HG, AF131215.7, AC055720.2, AC084375.1, LINC02471, DPP4-DT, AL162511.1, HMGA2-AS1, AL031985.3, AC141930.1, AC012038.2, TBILA, AL158206.1, FAM111A-DT, LINC02454, AC254633.1, AC005479.2, AC007255.1 and LINC00900) that were shared by three lncRNA sets, and these 22 lncRNAs were defined as prognostic differentially expressed FRLs between normal and tumor tissues (Fig. 2A–D). The gene discussed is DPP4; the disease is neoplasm.