Abstract: The present invention relates to tetracyclic pyrimidines or pyridines or pharmaceutically-acceptable salts or derivatives thereof. Also included are methods of use of the tetracyclic pyrimidines or pyridines including use related to treating inflammation, inhibiting T cell activation and proliferation, arthritis, organ transplant, ischemic or reperfusion injury, myocardial infarction, stroke, multiple sclerosis, inflammatory bowel disease and many other related disorders in a subject, the methods comprising administering a therapeutically-effective amount a compound as described above to the subject.