A newly isolated Burkitt lymphoma cell line, ROS-1, carrying the specific translocation (8;14) has been studied using somatic cell hybridization techniques. As in other reported Burkitt cell lines, the oncogene c-myc was found to be translocated from the 8q- to the 14q+ chromosome. In contrast to other reports, expression of the mu immunoglobulin (Ig) heavy chain correlated with the presence of the 14q+ derivative and not of its normal homologue. These results indicate that the translocation (8;14) is not necessarily an abortive event for the production of the mu Ig heavy chain by the 14q+ derivative.