FOLH1 and bone metastasis: With the presence of bone metastasis on 99mTc-PSMA (yes = 1, no = 0) as the dependent variable and age, serum PSA level, and the Gleason score as the independent variables, binary logistic regression analysis showed that serum PSA was independently correlated with the presence of bone metastases on 99mTc-PSMA: specifically, for every 1 ng/mL increase in serum PSA level, the detection rate of bone metastases increased by 4.4% (OR = 1.044, P < 0.001) (Table 5).