Morphologic and flow cytometric analysis of BM cells (Fig 1A) showed a diffuse infiltration of lymphoid blasts negative for CD3, CD2, CD1a, CD8, CD4, CD33, CD117, CD56, and CD10 and positive for CD7, CD38, CD99, cCD3, deoxynucleotidyl transferase, CD34, CD13, CD5 (45%), and HLA-DR, consistent with a diagnosis of ETP ALL.10 Cytogenetics showed a normal diploid karyotype. Here, CD5 is linked to acute lymphoblastic leukemia.