MTDH and osteosarcoma: To further assess whether miR‐22 was directly targeting MTDH expression through the target site in the 3′‐UTR of MTDH, reporter constructs containing either the wild‐type (WT) MTDH 3′‐UTR or MTDH 3′‐UTR with mutation (MUT) at the predicted miR‐22 target sequence were co‐transfected into osteosarcoma MG‐63 cells and then transduction of control, mimic NC, miR‐22 mimics, inhibitor NC or miR‐22 inhibitor.