CD19 and acute lymphoblastic leukemia: We applied SPD to a B-cell differentiation dataset [21], in which 9365 genes were measured for 44 samples across 5 normal differentiation stages and 1 malignant stage: 7 hematopoietic stem cells (HSC), 7 common lymphoid progenitors (CLP), 7 proB cells, 7 preB cells, 7 Immature B cells (IM), 5 more terminally differentiated B cells (1 naive B cell, 1 centroblast CB, 1 centrocyte CC, 1 memory B cell, 1 CD19+ cell), and 4 preB-ALL cancer samples.