The RNA-sequence dataset obtained from the public domain of The Cancer Genome Atlas (TCGA) and The Genotype-Tissue Expression (GTEx) project revealed that the correlation (R value) between the expression of DKK1 and FOXM1 mRNAs is higher in pancreatic and esophageal tissues, including tumor and non-tumor regions, compared with other tissues (Fig. 1D). This evidence concerns the gene DKK1 and neoplasm.