Several other genes have been identified with loss-of-function mutations that are associated with a predisposition to develop GPP; namely, CARD14 (caspase-activating recruitment domain member 14, also known as CARMA2) (49, 50), AP1S3 (adaptor protein 1 complex subunit sigma 3 (51, 52), MPO (myeloperoxidase) (53, 54), SERPINA3 (serine protease inhibitor A3) (55), and possibly SERPINA1 (56). Here, MPO is linked to psoriasis 14, pustular.