TLR4 and gout: Similarly, monosodium urate (MSU) crystals, which are common pathogenic uric acid crystals, have been implicated in studies where TLR2/TLR4 mediate their recognition, while others have suggested that MSU is opsonized by complement/antibodies for phagocytosis by macrophages, ultimately ​​promoting​​ gout inflammation [49–51].