PKM and rheumatoid arthritis: We analysed SDHB and PKM2 concentrations in the PBMC fraction to further investigate the clinical significance of SDHB and PKM2 relative gene expression in the peripheral blood of patients with RA; we observed that at baseline, SDHB and PKM2 protein expressions in PBMCs were significantly lower in patients with RA who achieved remission than in other patients with RA (Figure 1C,D).