Phenotype of CD45^bright myeloma cells. The phenotype of myeloma cells from 4 patients was determined in a 4-color assay. Myeloma cells were identified by coexpression of CD38 and CD138, and their phenotype (CD11a, CD19, CD27, CD28, CD56, Apo2.7) was analyzed in both CD45^weak/neg and CD45^bright subsets. Ig indicates immunoglobulin.