METTL3 and neoplasm: To investigate whether miR‐186 could regulate tumour development in vivo, HuH‐6, Hepa1‐6 and HCCLM9 cells were transfected with different lentivirus vectors and cells stably overexpressing miR‐186, overexpressing METTL3, silencing METTL3 and knockdown miR‐186.