PRG4 and avascular necrosis: In the analysis of EV proteins, fibronectin 1 (FN1), VWF, immunoglobulin heavy variable (IGHV)3–23, fibrinogen beta chain (FGB), immunoglobulin lambda variable 3 − 1 (IGLV3-1), proteoglycan 4 (PRG4), peroxiredoxin-1 (PRDX1), and spastic ataxia of Charlevoix (SACS) levels were elevated in patients with AVN.