CXCL8 and bacterial infectious disease: Hatzistilianou et al. (2010) [7] further validated IL-8’s role in pediatric ALL patients with chemotherapy-induced neutropenia, demonstrating significantly higher IL-8 levels in bacterial infections (neutropenic: 145.4 pg/mL; non-neutropenic: 176.1 pg/mL) compared to viral/FUO episodes (58.2–42.5 pg/mL; p < 0.001).