Doerflinger et al. (2021) [16] analyzed 79 FN episodes, showing PCT ≥ 0.425 ng/mL + IL-10 ≥ 4.37 pg/mL achieved 100% sensitivity (95% CI: 68.8–100%) and 89% specificity (95% CI: 80.0–95.0%) for bacteremia, correctly classifying all eight cases. The gene discussed is CALCA; the disease is bacterial infectious disease with sepsis.