THBS1 and rheumatoid arthritis: Citrullination of TSP-1, β-actin, and PF4 led to exposure of epitopes recognized by ACPA may facilitate our understanding of the role of ACPA in RA development by providing evidences for previous observations involving platelet activation by ACPA in RA (20), the elevated levels of PDPs associated with disease activity (16, 48), and possibly the increased risk of cardiovascular events observed in RA patients (49).