The disease affects adults and has a peak incidence in the fourth decade of life.[4,5] The Yamaguchi criteria are commonly used to diagnose AOSD and require the presence of 5 or more features, including fever, arthritis, typical rash, leukocytosis, sore throat, lymphadenopathy, hepatosplenomegaly, and negative rheumatoid factor and ANA tests.[6] Based on the medical history provided, the patient’s symptoms are consistent with AOSD. The gene discussed is BTG3; the disease is adult-onset Still disease.