Nonetheless, it was reported that leukemic blasts directly obtained from CML patients expressed fewer fMLP receptors than normal PBMCs; their chemotactic index (mobility) required fMLP concentrations of 10–100-fold higher than those required for normal PBMCs, but their PAF and LTB4 chemotactic pathways were preserved56,57. This evidence concerns the gene FPR1 and chronic myelogenous leukemia, BCR-ABL1 positive.