HSPD1 and rheumatoid arthritis: In a study on PBMC of RA patients, it was observed that pan-DR-binding human Hsp60 peptides induced 5- to 10-fold higher IL-10/tumor necrosis factor-α (TNF-α) ratio than that by microbial peptides, indicating immunomodulatory activity of self-Hsp60 peptides (24).