HOTAIR and retinoblastoma: For example, HOTAIR could bind to inter‐cellular miR‐331‐3p and miR‐124 based on its characteristic RNA sponging, thereby up‐regulating cancer cells’ capacity to reproduce.26 The sponging relationship between HOTAIR and miR‐613 was also manifested within carcinomas, such as non‐small cell lung cancer and pancreatic cancer.27, 28 The miR‐613 herein was suggested as a suppressor for retinoblastoma formation by targeting E2F5.29 However, whether HOTAIR could sponge miR‐613 to modulate osteosarcoma progression remained inconclusive.