XIAP and rheumatoid arthritis: qRT-PCR and western blotting showed that miR-431-5p mimics significantly reduced the mRNA and protein levels of XIAP (p = 0.018 and p = 0.0069, respectively, Fig. 4c–e), while XIAP levels were induced in HFLS-RA cells after transfection with the inhibitor (p = 0.0108 and p = 0.0007, respectively).