A flow cytometric investigation of peripheral blood found an abnormal lambda monotypic B-cell population suggestive of B-CLL ([cluster of differentiation: CD] CD19+, CD22 dim+, CD23 dim+, CD5+CD19+, CD5+CD23+, FMC7−; negative for myeloma cells [CD45−/CD19−/CD38+/CD56+/CD138+]). The gene discussed is CD5; the disease is plasma cell myeloma.