IL1B and rheumatoid arthritis: Similar to the result presented in MH7A cell lines, a significantly elevated OPG and RANKL expression and OPG/RANKL ratiowereobserved in IL1β-induced primary RA-FLS in the presence of 1,25(OH)2D3 compared with thosein theabsence of it (Figures 2(c) and 2(d)).