GDF15 and posterior cortical atrophy: Using logistic regression, two panels were identified among all panels of up to 4 markers (including phi but excluding PSA and %fPSA) to offer the most improvement in ROC/AUC over that of phi alone in separating AG from low risk PCa (AUCphi+Fuc-PSA+SDC1+GDF-15 = 0.942 vs AUCphi = 0.872) or from low risk PCa and non-PCa (AUCphi+Fuc-PSA+SDC1+Tie-2 = 0.934 vs AUCphi = 0.898) (Figures 3A and 3B).