Ebrahimi F, et al. - In this secondary analysis of two independent multicenter randomised controlled trials in patients presenting to the Emergency Department with community-acquired pneumonia, the pattern of FGF21 as well as associations with disease severity and outcome were studied. A total of 509 patients were analyzed for 30-day mortality, length of hospital stay, time to clinical stability and duration of antibiotic treatment. In moderate-to-severe CAP, a strong correlation between FGF21 levels at admission and disease severity, as measured by pneumonia severity index, was evident. In relation to increased levels of FGF21, researchers reported a prolonged time to clinical stability, antibiotic treatment and hospitalisation. In non-survivors vs in survivors, a significantly higher FGF21 levels at admission were detected, yielding a 1.61-fold increased adjusted odds ratio of 30-day mortality (95% CI, 1.21–2.14; p=0.001). In comparison to routine diagnostic markers, FGF21 demonstrated superior discriminative power to identify patients for 30-day mortality.