Precisely how many of the high grade (G4/5) PCa will fail to develop metastasis is nearly impossible to ascertain in human cases; nevertheless, if one assumes that the entire group of 52 (74%) primary G4/5 PCa cases that did not display PLZF loss lacks metastatic potential, the specificity of PLZF in predicating metastasis would be much higher than the reported 50% for PTEN [37]. The gene discussed is PTEN; the disease is posterior cortical atrophy.