GPRC6A and posterior cortical atrophy: Intriguingly, the member of the regulatory factor X family of transcription factors RFX6 gene variant rs339331 associated with a decreased PCa risk (C-allele OR 0.64, 95% CI:0.5–0.82, P = 4.6E−04) was in strong linkage with GPRC6A rs2274911 (r2 = 0.95).