DKK4 and hemoglobin measurement: To further evaluate the potential of DKK4 to only identify HB, we conducted ROC curve analysis and found that DKK4 showed a stronger diagnostic value (AUCtest = .848; AUCvalidation = .809) than AFP (AUCtest = .749; AUCvalidation = .719), whereas the combination of DKK4 and AFP exhibited the strongest diagnostic value (AUCtest = .863; AUCvalidation = .839) (Figure 8H,L).