In 2006, Manki et al. described two Japanese siblings with TRAPS (caused by the missense C30Y TNFRSF1A mutation in both) who presented pleural involvement and a characteristic decrease of serum soluble TNF-receptor, initially misdiagnosed as systemic-onset juvenile idiopathic arthritis at onset, suggesting that TRAPS can be frequently overlooked or misdiagnosed, and that TRAPS should be considered in all pediatric patients with atypical recurrent inflammatory manifestations [32]. The gene discussed is TNFRSF1A; the disease is TNF receptor 1-associated periodic fever syndrome.