We investigated whether TLR/IL-1R ligands can activate PKD1 and whether PKD1 plays a role in TLR/IL-1R-mediated proinflammatory gene expression in human fibroblast-like synoviocytes isolated from donor without rheumatoid arthritis (HFLS-N) or with rheumatoid arthritis (HFLS-RA). Here, PKD1 is linked to rheumatoid arthritis.