Aljaberi N, Tronconi E, Schulert G, et al. - Experts designed a retrospective analysis to examine the use of S100 proteins in a pediatric clinical setting for evaluating disease activity and supporting the diagnosis. They enrolled a total of 136 individuals who had S100 proteins tested as part of clinical care and relevant information collected from the medical record: C-reactive protein (CRP), disease activity status, systemic symptoms in systemic JIA (sJIA), and symptoms of the flare of other autoinflammatory and fever syndromes. They divided individuals into sJIA, non-systemic JIA (nsJIA), other specified autoinflammatory syndromes and systemic undifferentiated recurring fever syndromes. It was noted that sJIA individuals have markedly higher levels of S100A8/9 and S100A12 proteins which may assist with diagnosis in comparison with other autoinflammatory and fever syndromes, diagnosis. The data showed that S100 proteins may aid in monitoring disease activity in sJIA individuals.