Subsequent studies identified IL-2 receptor-α (CD25) [86], dipeptidyl peptidase 4 (DPP4, CD26) [85], Siglec-3 (CD33) [85], scavenger receptor-B2 (SR-B2, CD36) [85, 87], and IL-1 receptor accessory protein (IL-1RAP) [85, 88] as surface markers expressed predominantly by CML LSCs (Table 2). This evidence concerns the gene DPP4 and chronic myelogenous leukemia, BCR-ABL1 positive.