Genetic factors in SJIA include the presence of the human leukocyte antigen (HLA)—Bw35, DR2, DR4, DR5, and Dw7— as well as the presence of macrophage migration inhibitory factors (MIFs), IL6, IL18, TNFα polymorphisms, and, in AOSD, HLA- Bw35, DR2, DR4, DRB1, Dw7, and MIFs, which are IL18 polymorphisms [5]. This evidence concerns the gene TNFRSF10B and adult-onset Still disease.