Based on previous studies showing that MTA1 overexpression in the prostate enhances and accelerates PIN development in Pten+/f mice [12,13], we hypothesized that MTA1 overexpression in the context of PTEN loss-of-function (Ptenf/f) would increase the aggressiveness of prostate cancer progression and might even result in metastasis. The gene discussed is PTEN; the disease is prostate cancer.