Remarkably, PSA level as a marker of tumor load correlated with our measures of bone involvement (MVol R = 0.46, p < 0.01; number of manually counted lesions R = 0.67, p < 0.001; mean HU of MVol R = 0.42, p < 0.01; mean HU BVol R = 0.52, p < 0.001; and MVol/BVol ratio R = 0.75, p < 0.001). Here, KLK3 is linked to neoplasm.