Lymphoblastoid interferon improves long-term response to a six month course of treatment when compared with recombinant interferon alpha 2b: Results of an international trial St. Louis U, U Sidney, Australia, Hospital Beaujon, Clichy, France, Virchow-Klinikum, Berlin, Hospital Ramon y Cajal, Madrid, Mt. Sinai Hospital, Toronto, Ospedale Molinette, Turin, Italy, UCSF, Burroughs Wellcome Co.