ALDH+ cells have been reported to possess higher tumorigenicity in a variety of tumors, such as breast, liver, and lung tumors [42], [43], [44], including osteosarcoma [11], though for osteosarcoma the enhanced tumorigenicity was achieved after serial passaging of Os 99-1 osteosarcoma cells in mice. This evidence concerns the gene LDHA and osteosarcoma.