TCHP and posterior cortical atrophy: In the HRPCa EWAS, the top associated variants were in several genes relevant to PCa, including MKI67, PCSK6, ABCB6, and TCHP. MKI67 encodes the Ki67 protein, a widely used diagnostic marker of proliferation in numerous human cancers, with increased expression associated with poor prognosis in localised PCa40.