Dysregulated activation of the cyclin-dependent kinases CDK2 and CDK4 has likewise been closely linked to tumorigenesis, with recent studies [54, 55] showing that persistent CDK2 and CDK4 activation not only supports tumor cell proliferation, invasion, and metastasis but may also contribute to chemoresistance, making them important therapeutic targets. The gene discussed is CDK2; the disease is neoplasm.