It has been reported that PCT had the better discriminative power than CRP to differentiate not only TF from LBI (localized bacterial infection) (AUC was 0.840 for PCT and 0.786 for CRP) [1], but also bacteremia from nonbacteremia in cancer patients with febrile neutropenia (AUC was 0.748 for PCT and 0.655 for CRP) [53], as well as bacterial infection from other causes of fever in pediatric oncology patients with febrile neutropenia (AUC was 0.769 for PCT and 0.596 for CRP) [54]. Here, CALCA is linked to bacterial infectious disease.