S100B and idiopathic pulmonary arterial hypertension: Furthermore, they analyzed the structure of the Golgi apparatus in lung tissue sections of pulmonary vascular lesions in idiopathic PAH (IPAH) and in macaques infected with a chimeric simian immunodeficiency virus containing the human immunodeficiency virus (HIV)-nef gene (SHIV-nef) with histological evidence of proliferative, obliterative, and/or plexiform arterial lesions, using subcellular three-dimensional (3D) immunoimaging.