CYLD and rheumatoid arthritis: We showed that CYLD knockdown visibly aggravated NF-ΚB activity in RA-FLSs nuclei and IκBα in RA-FLSs cytoplasm and obviously decreased the level of total IκBα in RA-FLS cytoplasm (Fig. 6a), but not the total of NF-κB in RA-FLSs (Figs. 4a and 6b).