LINC00665 and gastric cancer: Gene Expression Profiling Interactive Analysis (GEPIA) was adopted to analyze significant differences between the 21 lncRNAs provided in the STAD data of The Cancer Genome Atlas (TCGA) database in normal tissues and GC tissues, and we determined that SNHG12, LINC00665, and TTN-AS1 were expressed in GC tissues with the top 3 largest differences (Fig. S1B).