PRKD1 and rheumatoid arthritis: In summary, we have demonstrated that TLR and IL-1R ligands induce activation of PKD1 in HFLS isolated from donors with or without RA, and that PKD1-knockdown or inhibition of PKD by Gö6976 treatment substantially inhibits TLR/IL-1R-mediated proinflammatory cytokine/chemokine expression in HFLS-RA.