Ubiquitin modification levels on TRAF6 and TRAF3. When the 293T cells reached to 70% to 90%, Flag-TRAF3 or Flag-TRAF6, Myc-PLP, HA-Ub plasmids were transfected, and the myricetin treated group was added with 100 μM myricetin 24 h after transfection. 48 h post-transfection, the cells of each sample were collected to extract total proteins. Part of the extracted total proteins was used for Input detection; the other part of the protein was incubated with anti-Flag antibody and Protein G overnight at 4°C, and centrifuged to collect magnetic beads to obtain protein precipitate for COIP detection. Abbreviations: TRAF3 and TRAF6, tumor necrosis factor receptor-associated factor 3 and 6.