Negative regulators of PTEN gene expression include mitogen-activated protein kinase kinase-4, transforming growth factor beta (TGF-β), nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-κB), IGF-1, the transcriptional cofactor c-Jun proto-oncogene, and the B-cell-specific Moloney murine leukemia virus insertion site 1 (BMI1) proto-oncogene, which have been shown to suppress PTEN expression in several cancer models [30–32]. The gene discussed is PTEN; the disease is cancer.