The objective of this surveillance is to determine the following items in all patients receiving Enbrel for a certain period after marketing: 1) unlabeled adverse events, 2) onset (frequency, severity and other details) of adverse events, 3) factors considered to affect the safety, and 4) the efficacy of Enbrel. Moreover, the onset (frequency, severity and other details) of the followings will be key issues of this surveillance:Infection (tuberculosis, opportunistic infection, etc.), autoimmune diseases, cardiac failure, malignant tumor, interstitial pneumonia, demyelinating disorders, pancytopenia, aplastic anemia and application site reactions.