BDNF and sarcoidosis: We have previously reported elevation of NGF in BALF of sarcoidosis patients [4], and this study confirms those results, and extends them by including the analysis of the neurotrophins NT-3 and BDNF in both BALF and serum, and by identifying cellular sources of, and targets for, NGF, BDNF and NT-3 in the lungs of sarcoidosis patients.