Abstract
Seven θ+murine lymphomas in culture are very sensitive to killing by phytohemagglutinin; myeloma cell lines and a myeloid leukemia in culture are resistant. Pokeweed mitogen exerts an inhibitory effect both on lymphomas and myelomas, but only at high concentrations. Most of the lymphomas are inhibited by 10-6 M cortisol whereas myeloma cells are generally resistant to the steroid at 10-4 M. However, some IgA myelomas are as sensitive as lymphomas.