Anti‐CD9 has already been used in vitro and could induce apoptosis of Jurkat cells and inhibition of proliferation of B‐ALL cells.25, 28 CD9 is also widely expressed on monocytes and depletion of these cells could be interesting in AML as they are implicated in disease progression by producing interleukin‐1.29 This evidence concerns the gene CD9 and acute myeloid leukemia.