Korea University Research and Business Foundation (KURBF) has identified adamantyl derivatives acting as dipeptidyl peptidase 4 (DPP4; CD26) inhibitors reported to be useful for the treatment of cancer, autoimmune disease, Parkinson's disease, nonalcoholic steatohepatitis (NASH), rheumatoid arthritis, aortic valve stenosis and cerebrovascular and dermatological disorders.