Accumulated reports have demonstrated the role of HOTAIR in cellular processes as a ceRNA: HOTAIR can stimulate the development of glioma, serving as a ceRNA via sponging miR‐126‐5p33; HOTAIR promotes to the progression of gastric cancer by acting as a ceRNA of miR‐331‐3p, which is mediating HER2.34 Moreover, down‐regulation of HOTAIR decreased the expression of Vimentin and MMP‐9 but increased that of E‐cadherin through up‐regulation of miR‐204. This evidence concerns the gene MMP9 and gastric cancer.