Results: Principal component analysis (PCA) revealed a clear distinction between pulmonary sarcoidosis and healthy control groups, with 227 differentially expressed genes (88 upregulated, 139 downregulated), including upregulated (CLEC7A, GBP5, JAK2, IL15, IL1B, CXCL8, and CXCL10) and downregulated (TNFRSF13C, CD40LG, CD28, and ID3) genes in pulmonary sarcoidosis group. The gene discussed is CD28; the disease is pulmonary sarcoidosis.