The combined effect of human lymphoblastoid interferon (HLBI) and anticancer agents on the growth of MOLT-4 was studied in vitro. The interferon showed a strikingly synergistic interaction in combination with aclarubicin, cytosine arabinoside or prednisolone. It was moderately synergistic in combination with adriamycin or 5-fluorouracil and tended to show additive effects with daunorubicin or vincristine. In vitro studies of combination chemotherapy with interferon and anticancer agents should yield valuable information as to the best combination for man.</p
