Regarding the miR-33a family, it was demonstrated that high mobility group AT-hook 2 (HMGA-2) is a target of miR-33a-5p during osteoblast commitment, and that miR-33a is up-regulated in chemoresistant osteosarcoma and promotes osteosarcoma cell resistance to cisplatin by down-regulating TWIST (an EMT transcriptional factor) [27,28,29]. This evidence concerns the gene TWIST1 and osteosarcoma.