The objectives of this research program are to investigate and evaluate myeloma cells as neoplastic cells and also as cells which possess many of the characteristics of normal antibody synthesizing cells. This will be done largely by utilizing continuous suspension cell cultures which we have established. In working toward these goals we will continue to collect and correlate biological, ultrastructural and biochemical (functional) data with the goal of understanding the interrelationships among these various parameters. The specific problems to be studied are: (1) To examine the oncogenic potential of murine myeloma cells which have been cultured in vitro. The characteristics of loss of oncogenicity observed to occur spontaneously in cultured cells will be characterized in vivo and the accompanying known increase in immunogenicity will be examined. (2) In vitro techniques for the measurement of cellular immune responses will be studied. (3) Factors which may affect oncogenicity, i.e. mutation, which may be recognizable in banded karyotypic analysis, loss or gain of viruses, or alterations in surface membranes will be studied. Other phenotypic changes which may occur, such as alterations in globulin synthesis, growth or ultrastructural changes will be monitored and relationships studied. The effect of factors which may specifically bring about any one of these changes will be examined. These studies will be extended to human myeloma cells to the extent that the material is available.