Further strong evidence comes from a recent investigation of the impact of cytoplasmic p21 on tumorigenesis in vivo [132]: MMTV/neu mice expressing cytoplasmic p21 (T145D, mimicking the Akt phosphorylation) in the mammary epithelium had an accelerated tumor onset as well as enhanced lung metastasis indicating an oncogenic role of p21 [132]. The gene discussed is CDKN1A; the disease is neoplasm.