PTPγ has been proposed as a tumor suppressor gene whose expression is lost in various neoplastic diseases including renal cell carcinoma, lung, ovarian, breast and colorectal cancers (LaForgia et al. 1993, Lubinski et al. 1994, Tsukamoto et al. 1992, van Niekerk and Poels, 1999, Liu et al. 2004, Wang et al. 2004, Vezzalini et al. 2007). The gene discussed is PTPRG; the disease is neoplasm.