PCAL has a better positive predictive value than CRP for febrile infants less than 2 months5,6 and in the diagnosis of sepsis.7 PCAL may help exclude typical bacterial pneumonia,8 but variability between studies suggests an inconsistent ability to distinguish between viral and bacterial etiologies reliably.9,10 Although there is good evidence to support PCAL-guided de-escalation of antibiotics in sepsis,11 it is essential for providers to consider various factors such as site of infection, microbial etiology, and the patient’s response to initial treatment. This evidence concerns the gene CRP and Sepsis.