The results showed that lncRNA WFDC21P, CYTOR, XIST, and AK093987 were significantly upregulated in GC according to the Cancer Genome Atlas (TCGA) database (Supplementary Fig. A), and lncRNA WFDC21P was most significantly upregulated in 12 GC tissues compared with matched normal tissues (p = 0.005, Supplementary Fig. B). This evidence concerns the gene XIST and gastric cancer.