The present invention includes a method of determining a lung disease from a patient suspected of sarcoidosis, tuberculosis, lung cancer or pneumonia comprising: obtaining a sample from whole blood of the patient suspected of sarcoidosis, tuberculosis, lung cancer or pneumonia; detecting expression of (although not exclusive) six or more disease genes, markers, or probes selected from SEQ ID NOS.: 1 to 1446, wherein increased expression of mRNA of upregulated sarcoidosis, tuberculosis, lung cancer and pneumonia markers of SEQ ID NOS.: 1 to 1446 and/or decreased expression of mRNA of downregulated sarcoidosis, tuberculosis, lung cancer or pneumonia markers of SEQ ID NOS.: 1 to 1446 relative to the expression of the mRNAs from a normal sample; and determining the lung disease based on the expression level of the six or more disease markers of SEQ ID NOS.: 1 to 1446 based on a comparison of the expression level of sarcoidosis, tuberculosis, lung cancer, and pneumonia.