MMP7 and breast angiosarcoma: Serum MMP-7 achieved an AUC value of 0.947 (95% CI: 0.902–0.992) in differentiating BA in neonates aged 0–30 d, with a cutoff value of 28.1 ng/mL achieving the best diagnostic performance for this group, a sensitivity, specificity, PPV, and NPV of 86.4% (95% CI: 75.0–94.0%), 95.5% (95% CI: 77.2–99.9%), 98.1% (95% CI: 89.7–100%), and 72.4% (95% CI: 52.8–87.3%), respectively (Fig. 4; Table 2).