Analysis of LUAD datasets from the NCBI GEO database revealed that GRPR expression was significantly higher in tumor tissues than in normal tissues (p = 3.4 × 10−3 for GSE31210; p = 3.9 × 10−5 for GSE19188; p = 2.3 × 10−2 for GSE19804, t-test, Figure 1a). This evidence concerns the gene GRPR and neoplasm.