Noncycling Tumor Cells: Mitogenic Response to Antilymphocytic Serum

Abstract
After continuous labeling with tritiated thymidine for a period several times the cell generation time, some ELD ascites cells remained unlabeled. Despite continued exposure to tritiated thymidine, unlabeled mitoses appeared promptly after administration of mouse antilymphocytic serum. Immunosuppression released some noncycling G2 tumor cells into mitosis.