TNFSF11 and rheumatoid arthritis: Given previous study reported that only IL1β or IL-6 plus soluble IL-6 receptor (but not IL-6 alone) could show the ability to induce RANKL expression in vitro after RA fibroblast-like synoviocyte treatment with TNFα, IL-6, IL-17, and IL1β [20], we stimulated MH7A cells with IL1β in current study.