STIM1 and rheumatoid arthritis: The representative blots are shown in Fig. 4A. The expression levels of ORAI1, STIM1, and CRACR2A in the normal and RA FLS cells were 104.07 ± 12.08 and 96.30 ± 25.31, 68.46 ± 6.09 and 84.48 ± 6.72, and 38.81 ± 6.77 and 52.04 ± 8.55 AU, respectively, indicating that the proteins, except for ORAI1, exhibited significantly higher expression in the RA FLS cells than in the normal FLS cells (p > 0.01) (Fig. 4B).