BDNF and sarcoidosis: Among the identified pathways, the HIF-1 (26, 27) and neurotrophin (28) signaling pathways, whose corresponding target genes were MAPK1, SERPINE1 and CAMK2D for HIF-1 signaling pathways and CDC42, MAPK1, MAP3K3, and CAMK2D for neurotrophin signaling pathways in our analysis, have been implicated in the inflammation pathogenesis of sarcoidosis according to previous studies.