Retraction of ‘Elevation of USP4 antagonizes oxygen glucose deprivation/reoxygenation-evoked microglia activation and neuroinflammation-mediated neurotoxicity via the TRAF6-NF-κB signaling’ by Zhaoxia Wang, RSC Adv., 2019, 9, 23916–23924, DOI: 10.1039/C9RA03614H.