ANXA1 and Osteopenia: However, for annexin A1, when nonosteoporotic controls were compared with osteopenia, the area under the ROC curve was 0.805 (Figure 4(a), 95% CI 0.682 to 0.928; sensitivity 0.588, specificity 0.917) and when compared with osteopenia and osteoporosis combined, the area under the ROC curve was 0.833 (Figure 4(b), 95% CI 0.729 to 0.938; sensitivity 0.588, specificity 0.93).