Using bioinformatic analyses, luciferase reporter assay, and RIP assay, this study demonstrated that NKX2‐1‐AS1 could directly bind and inhibit miR‐145‐5p expression and indicated that miR‐145‐5p expression was significantly downregulated and negatively correlated with NKX2‐1‐AS1 expression in GC cells. This evidence concerns the gene NKX2-1 and gastric cancer.