The area under the curve (AUC) of Gal3C-S-OPN/uFL-OPN for discriminating stone forming urolithiasis patients (AUC, 0.945; 95%Cl, 0.915–0.976) provided significantly better clinical performance than that of uFL-OPN (AUC, 0.929; 95%Cl, 0.892–0.945, p = 0.0273). This evidence concerns the gene SPP1 and urolithiasis.