NFKB1 and rheumatoid arthritis: Combinatorial nanoparticles were more successful than individual medications at blocking NF-kB signalling pathways and reducing the expression of pro-inflammatory cytokines.79 Nanoparticles modified with PEG agglomerate widely in RA joints, enter the cell membrane via Sta-R8 (stearic acid-octa-arginine), and are absorbed by active macrophages via folate receptor-aided endocytosis.