Current studies suggest that alveolar macrophages (AM) act as silencers of most immune responses in the lung. However, in pathological conditions, such as asthma, hypersensitivity pneumonitis, and sarcoidosis, AMs become involved in the maintenance and further expansion of the immune response in the target organ. The Investigator has preliminary data demonstrating that CBD AMs at the site of disease involvement (bronchoalveolar lavage, BAL) display an activated cell surface phenotype compared to AMs from healthy controls. Furthermore, exciting data from our group demonstrates significant differences in gene expression profiles between CBD and Beryllium Sensitivity (BeS) bronchial alveolar lavage (BAL) cells, in pivotal immune response genes and networks. Specifically, the Investigator has found the JAK/STAT pathway and the JAK2 gene was dramatically overexpressed in CBD BAL cells. In addition, constitutively phosphorylated JAK2 (pJAK2) was found in AMs from Chronic Beryllium Disease (CBD) patients by Westernblot and was increased after beryllium (Be) stimulation for 30 min. Moreover, the JAK2 inhibitor TG101348 significantly inhibited Be-induced CBD AMs TNFa and IFNy production. Meanwhile, overexpression of the JAK2 inhibitor SOCS 1 (suppressors of cytokine signaling) protein decreased Be-induced TNFa production from AMs. Based on this information, the Investigator hypothesizes that CBD AMs overexpress JAK2, which augments the immune response to Be and development of CBD but not BeS.