Specifically, in mice older than 28 weeks containing various combinations of global Cdkn1a/Cdkn1b deletion in addition to a Cdk4 mutation (i.e., hetero- or homozygous deletion/mutation), between 9 and 56% of all spontaneously formed tumors were angiosarcomas [122, 161]. The gene discussed is CDK4; the disease is angiosarcoma.