CXCR4 and acute myeloid leukemia: In a phase 1/2 study of chemo-sensitization with MZ in relapsed or refractory acute myeloid leukemia, a decrease in CD184-12G5 binding was observed from pre-treatment to 6 hours, followed by an increase from 6 to 24 hours, indicating CXCR4 blockade by MZ in vivo [52].