Endothelial progenitor cell-derived exosomes inhibit high-mobility group protein B1 (HMGB1) by overexpressing miR-126, which targets phosphoinositide 3 kinase regulatory subunit 2 (PIK3R2) and increases cell tight junction protein levels to relieve LPS-induced ALI [25]. Here, HMGB1 is linked to acute respiratory distress syndrome.