MMP9 and chronic recurrent multifocal osteomyelitis: Abbreviations; AAV, adeno‐associated virus; CD19, cluster of differentiation 19; miR, microRNA; MMP‐9, matrix metalloproteinase‐9; NF‐κB, nuclear factor kappa‐light‐chain‐enhancer of activated B cells; OPN, osteopontin; pCMFO, plasmid for chronic multifocal osteomyelitis; PDCD4, programmed cell death 4; PEI, polyethylenimine; P‐gp, P‐glycoprotein; TLR4, Toll‐like receptor 4; TRAIL, tumor necrosis factor‐related apoptosis‐inducing ligand; TTR, transthyretin; VEGF, vascular endothelial growth factor