HSPA4 and pulmonary arterial hypertension: Of these intracellular DAMPs, galectins (LGALS1 and LGALS3),53, 54 thioredoxin (TXN and TXN2),55, 56 cyclophilin A,57 HSPs (HSP90B1 and HSPA4)58 and S100 proteins (S100A3 and S100A4)48, 59 have already been demonstrated to mediate pulmonary vascular remodelling, although they were not known as intracellular DAMPs in the PAH field.