Although procalcitonin (PCT) does not appear to provide added value over C-reactive protein (CRP) in identifying serious bacterial infections (SBI) in all febrile children [1, 3], several studies, including a systematic review published in 2024, demonstrate that PCT is superior to CRP in detecting invasive bacterial infections (IBI), such as sepsis, but not SBI, such as pneumonia, in febrile children without an apparent source [2, 4, 5]. The gene discussed is CRP; the disease is pneumonia.