KAT6A-deficient mouse embryonicfibroblasts (MEFs) showed impaired p53-mediated expression of theCyclin-Dependent Kinase Inhibitor 1A(CDKN1A, encoding p21) gene and failed to arrest in theG1 phase, suggesting that the loss of KAT6A-p53 complex-mediated p21expression contributes to tumor pathogenesis and leukemogenesis. This evidence concerns the gene CDKN1A and neoplasm.