Similarly, conditional deletions of Pten from primordial germ cells, the prostate, the pancreas, mammary epithelium, thyrocytes, the liver, or the smooth muscle cell lineage in mice have been reported to be associated with teratomas, prostatic cancers, pancreatic cancers, breast cancers, thyroid cancers, cholangiocellular carcinomas, and leiomyosarcomas, respectively [reviewed in reference 3]. The gene discussed is PTEN; the disease is breast cancer.