However, it may be helpful to discriminate disease from normal B-cell precursors during minimal B-ALL disease assessment.1,2 The ClearLLab 10C system also lacks markers to discern CD5-positive and CD5-negative mature B-cell lymphoproliferative disorders (LPD), using markers such as CD23, CD43, CD79b, CD81, and ROR-1 recommended for classification by Rawstron et al.17,18 Investigation of PCD is also limited if investigated only with the ClearLLab 10C system which lacks CD138, an absolute requirement for identifying plasma cells together with CD3819. The gene discussed is CD5; the disease is precursor B-cell acute lymphoblastic leukemia.