CDK6 and osteosarcoma: MiR-491-5p has already been described as a tumor suppressor in various cancers and several of its direct targets have been identified and include Bcl-xL in colorectal cancer [21], Bcl-xL and EGFR in ovarian cancer [19], Bcl-xL and TP53 in pancreatic cancer [20], Bcl-xL, EGFR and CDK6 in glioblastoma [22], Pyruvate Kinase M2 (PKM2) [38] and Forkhead box Protein P4 (FOXP4) in osteosarcoma [39], the most common type of bone cancers.