Polyubiquitination profiles of TRAF6. The levels of Lys63- and Lys48-specific polyubiquitination (Ub) were investigated at day 10 by Western blotting (IB) after immunoprecipitation (IP) of TRAF6. A, polyubiquitination profiles in M-CSF/sRANKL (MR), M-CSF/LPS added at day 7 (ML) and M-CSF/sRANKL/LPS added at day 7 (MRL). **, p < 0.01 compared with MR; ##, p < 0.01 compared with ML. B, polyubiquitination profiles of PBMCs transfected with either nontargeting (NC) or A20 siRNAs ± LPS. Results were expressed as a specific ubiquitination:total TRAF6 ratio. **, p < 0.01 compared with untreated cells; ##, p < 0.01 compared with nontargeting siRNA. Error bars = S.E.