Our analysis on the expression of CCL3 receptors, CCR1 and CCR5, revealed that CCR1 and to a markedly lesser degree, CCR5, was expressed on normal lineage marker (lin)−c-kit+ progenitor cells and that CCR1 but not CCR5 expression was maintained by CML lin−c-kit+ progenitor cells [89]. Here, CCR1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.