S100A9 and sarcoidosis: MRP14 (myeloid-related protein 14), also known as S100A9, is intracellular calcium-binding protein, was found to be significantly elevated in bronchoalveolar lavage (BAL) samples from both sarcoidosis and idiopathic pulmonary fibrosis (IPF) patients, and its levels correlated with the stage of chest radiographs in sarcoidosis (Korthagen et al., 2010).