These alterations are similar to previous data, which MSCs derived from p21-/-p53+/-mice completely lost p53 expression after in vitro long-term culture and formed sarcomas in vivo [42] and muline MSCs derived osteosarcoma cells in consequence of aneuploidization and genomic loss of Cdkn2 [43]. The gene discussed is CDK2; the disease is osteosarcoma.