In contrast to IL-17A blockade by the research-use-only antibody, where still a significant difference in FoxP3-expression was seen between JIA and HC (p = 0.004), in vitro treatment with Secukinumab adjusted FoxP3-expression of JIA-derived Treg to normal levels found in HC (56.7% vs. 49.3%; p = 0.247). The gene discussed is FOXP3; the disease is juvenile idiopathic arthritis.