At the molecular level, the gene fusion TMPRSS2-ERG is one of the most conspicuous tumor signatures [18], and genome-wide association studies have identified alterations (i.e., point mutations, chromosome rearrangements, indels, and copy number variations) in more than 100 low-penetrance loci defining the molecular landscape of PCa [19]. The gene discussed is TMPRSS2; the disease is posterior cortical atrophy.